JP2005085933A - Optical sensor, and optical logic device, and electronic device using sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly functional optical sensor having various characteristics such as polarization and absorption characteristics, responses to multiple wavelengths, optical transmittance, photoelectric conversion efficiency distribution, and side irradiation optical response; and to provide an optical logic device and an electronic device using the optical sensor. <P>SOLUTION: The optical sensor includes at least two electrodes 2, 6 provided on a substrate 1, and a photoelectric conversion region 17 composed of at least one kinds of electron-donating organic material 15 and an electron accepting material 16 provided between the electrodes, and the photoelectric conversion region 17 having the polarization and absorption characteristics. The optical sensor is hereby obtained, which has the polarization response characteristics of outputting different electric signals in response to the differences of polarization planes of incident light. Further, it is possible to obtain the optical sensor having response characteristics to multiple wavelengths of responding to multiple wavelengths by controlling the absorption characteristics of a constituent material, and to obtain the optical sensor that transmits light by imparting optical transmittance to the constituent material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical sensor used for various position detections, optical communication, and the like, an optical logic element using the same, and an electronic device.

  With the rapid development of IT (Information Technology) society, the amount of information to be recorded or transmitted has become enormous, and it has become very important to increase the recording capacity and increase the information transmission speed. For this reason, recording media that have been recorded by electricity, magnetism, etc. have been changed to optical recording systems capable of increasing the density, and also in communication, the speed is increased by shifting the medium from electricity to light. The importance of light is increasing.

  What is important for such optical recording, optical communication, etc. is the type of light source to be used. However, research on various lasers has made it easier to obtain highly linear and coherent light. As a result, development is proceeding with a focus on this laser. Recently, among them, development for performing high-density recording by using light of a shorter wavelength blue region has been actively conducted.

  As important as the light source is the control and detection of light, and the importance of the optical sensor responsible for this function is increasing.

  Conventionally, a photodiode formed mainly from an inorganic silicon material has been used for this optical sensor, and almost all optical sensors such as an image sensor, a solid-state imaging device, and a photocoupler are formed of an inorganic material. .

  As described above, inorganic photosensors represented by silicon photodiodes are used in a wide range of fields, but conventional semiconductor processes such as large-scale vacuum film forming apparatuses and etching apparatuses are indispensable for the formation. Therefore, it is difficult to increase the size and cost. Furthermore, inorganic light sensors often contain elements such as In, Ga, As, and P, which have a great influence on the ecosystem, and have a problem that the environmental load of disposal is large.

  In recent years, an organic photoelectric conversion element that can be easily manufactured and has a large area has been developed (see, for example, Patent Document 1).

Here, a general organic photoelectric conversion element will be described. FIG. 5 is a cross-sectional view of a main part of a general organic photoelectric conversion element. As shown in FIG. 5, the organic photoelectric conversion element is made of ITO (Indium) formed on a light-transmitting substrate 1 such as glass by a sputtering method or a resistance heating vapor deposition method.
An anode 2 made of a transparent conductive film such as Tin Oxide), a photoelectric conversion region 3 in which an electron-donating layer 4 and an electron-accepting layer 5 are formed on the anode 2 by a resistance heating vapor deposition method, and the upper portion thereof And a cathode 6 made of metal formed by resistance heating vapor deposition or the like.

  When the organic photoelectric conversion element having the above configuration is irradiated with light, light absorption occurs in the photoelectric conversion region 3, and excitons are formed. Subsequently, carriers are separated, and electrons move to the cathode 6 through the electron-accepting layer 5 and holes move to the anode 2 through the electron-donating layer 4. As a result, an electromotive force is generated between both electrodes, and an electric signal can be taken out by connecting an external circuit.

The photoelectric conversion element is used as various optical sensors. One example is an image sensor. FIG. 6 is a cross-sectional view of a main part of a conventional image sensor. Here, 7 is a light source, 8 is a SELFOC lens (trade name), 9 is an optical sensor, and 10 is a document. The original 10 irradiated by the light source 7 is condensed by the Selfoc lens 8 and read by the optical sensor 9.
Japanese Patent Laid-Open No. 5-145098

  As described above, many conventional optical sensors simply detect light, and few have special functions. For example, conventional photosensors have poor selectivity for light that responds, making it difficult to respond only to light of any arbitrary polarization plane or wavelength, or providing light transparency is very difficult, There is a problem that it is necessary to branch light for sensing light, or that a sensor cannot be arranged in the middle of the optical path.

  Further, in the conventional optical sensor, it is difficult to individually detect light in a plurality of wavelength regions with the same sensor. For this reason, in order to detect light in a plurality of wavelength regions, it is necessary to arrange optical sensors corresponding to the number, and there is a problem in that space saving is hindered and cost is increased.

  Further, in the image sensor using the conventional optical sensor, as shown in FIG. 6, the light receiving portion of the optical sensor 9 does not have light transmission, so the light source 7 is disposed obliquely with respect to the optical sensor 9, It was necessary to irradiate the original 10. For this reason, the optical sensor 9 and the document 10 inevitably require a spatial distance, and various optical systems such as the SELFOC lens 8 are required to maintain the resolution. Due to such a configuration, the conventional image sensor becomes larger than necessary.

  In addition, since many of the conventional optical sensors do not have optical transparency, the light used for detection cannot be reused. For this reason, the light to be used and the light to be detected need to be branched, which increases the number of optical components and makes it difficult to reduce the size.

  The present invention solves the above-mentioned problems, and a highly functional optical sensor having various characteristics such as polarization absorption characteristics, multiple wavelength responsiveness, light transmission, photoelectric conversion efficiency distribution, and lateral irradiation light responsiveness, and the same It is an object of the present invention to provide an optical logic element and an electronic device using the above.

  The optical sensor of the present invention is composed of an organic photoelectric conversion element in which various characteristics are imparted to an organic material or the like constituting a photoelectric conversion region.

  The optical sensor of the present invention imparts polarization absorption characteristics to the photoelectric conversion region of the organic photoelectric conversion element. As a result, an optical sensor having a polarization response characteristic that outputs different electrical signals according to the difference in polarization plane of incident light can be obtained.

  In addition, the optical sensor of the present invention can obtain an optical sensor having a multi-wavelength response that responds to a plurality of wavelengths by controlling the absorption characteristics of the constituent materials, and can transmit light by making the constituent materials have optical transparency. An optical sensor can be obtained.

  Furthermore, the optical sensor of the present invention can control the light transmission characteristics of the substrate and the electrode and the film thickness of the photoelectric conversion region, so that the photoelectric conversion efficiency can be distributed within the same sensor, or the side incident light can be distributed. It becomes possible to respond.

According to the present invention, it is possible to provide a highly functional optical sensor and an electronic device using the same by imparting polarization response characteristics, multiple wavelength response, light transmission, photoelectric conversion efficiency distribution, side irradiation light response, and the like. Can be provided.

  In order to solve the above-mentioned problems, the invention of claim 1 is directed to an electron including at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, fullerenes and / or carbon nanotubes. It has a photoelectric conversion region composed of a receptive material, and is a photosensor having a polarization response characteristic that can output different electrical signals according to the difference in the polarization plane of incident light. In addition, since the element itself has a polarization response characteristic, a polarizer is unnecessary and a small polarization sensor can be obtained.

  The invention of claim 2 made to solve the above-described problem is that, in the optical sensor of claim 1, when the maximum value of the current output from the optical sensor having polarization response characteristics is Imax and the minimum value is Imin. Imax / Imin is larger than 2, and the element itself has a polarization response characteristic, so that a polarizer is not required and a small polarization sensor can be obtained, and an output ratio more than doubled. It becomes possible to improve the reliability of an electronic device using polarized light such as an optical switch.

  In order to solve the above-mentioned problems, the invention of claim 3 is characterized in that in the optical sensor of claim 1 or claim 2, the electron donating organic material in the photoelectric conversion region is oriented. In addition, by orienting the electron donating organic material, it is possible to easily impart polarization absorption characteristics to the photoelectric conversion region, and it is possible to provide an optical sensor having polarization response characteristics. The electron donating organic material may be oriented by any method that can orient the material, such as a rubbing method or stretching method, but a polymer material is used as the electron donating organic material. In such a case, it is convenient and preferable to use the rubbing method.

  In order to solve the above-mentioned problems, the invention of claim 4 is directed to an electron including at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, fullerenes and / or carbon nanotubes. It has a photoelectric conversion region made of a receptive material, absorbs light of multiple different wavelengths, and can output different electrical signals according to each wavelength, and each electrical signal can be distinguished It is characterized by being.

  It has been difficult for conventional optical sensors to absorb and detect light in a discontinuous and wide wavelength range. In other words, it is difficult to have a plurality of wavelengths to be detected and transmit light having a wavelength between them without detection. This cause is mainly due to the light absorption characteristics of the constituent materials. However, in the optical sensor of the present invention, for example, by mixing two types of electron donating materials, light in completely different wavelength regions can be detected by the same element. It becomes possible. Further, depending on the material selection, it is possible to prevent any reaction to light in a certain wavelength region.

  In order to solve the above-mentioned problems, the invention of claim 5 is directed to an electron including at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, fullerenes and / or carbon nanotubes. An optical sensor having a photoelectric conversion region made of a receptive material, wherein at least a part of the optical sensor has optical transparency.

Many of the conventional photosensors do not have optical transparency, so that the light used for detection cannot be reused. For this reason, the light to be used and the light to be detected need to be branched, which increases the number of optical components and makes it difficult to reduce the size. However, the optical sensor of the present invention itself has optical transparency and can transmit light other than the light used for detection, so that it is not necessary to branch the light for detection. Further, in a conventional image sensor or the like, it is necessary to separately arrange a light source and a light receiving unit for irradiating a document. However, since the optical sensor of the present invention is light transmissive, it is laminated with the light source unit. It is possible to expand the application range to each stage by imparting optical transparency to the optical sensor, such as enabling a large space saving.

  In order to solve the above-mentioned problem, the invention of claim 6 is directed to an electron including at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, fullerenes and / or carbon nanotubes. An optical sensor having a photoelectric conversion region made of a receptive material, characterized in that the photoelectric conversion efficiency of the optical sensor has a distribution within the same sensor. It is possible to obtain information on the position irradiated with. For example, when using a photosensor that increases the conversion efficiency at the center of the sensor and reduces the conversion efficiency as you move away from the center, it is possible to detect deviation from the center of the irradiated light as a decrease in electrical output. It becomes. The distribution of conversion efficiency can be obtained by giving a distribution to the transmittance of the substrate and the reflectance of the electrode, or by giving a distribution to the film thickness of the photoelectric conversion region.

  The invention of claim 7 made to solve the above problem is characterized in that, in the optical sensor of the invention of claim 6, the distribution of photoelectric conversion efficiency changes from the center of the sensor toward the outside. It is possible to obtain information on the position irradiated with light depending on the magnitude of the electrical output.

  The invention of claim 8 made to solve the above-mentioned problems is an electron comprising at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, fullerenes and / or carbon nanotubes. An optical sensor having a photoelectric conversion region made of a receptive material, characterized in that a side portion with respect to the stacking direction of the electrode and the photoelectric conversion region is a light receiving portion, and a cross-sectional area of the photoelectric conversion element It is possible to obtain a very small optical sensor having the same size as the above. In addition, it is possible to easily form an optical sensor having multi-wavelength response by using a plurality of stacked optical sensors having different absorption wavelengths.

  The invention of claim 9 made to solve the above-mentioned problems is characterized by having at least two of the functions of the photosensors of claims 1 to 8, and has a polarization response characteristic and a plurality of wavelengths. Since one sensor has a plurality of functions among responsiveness, light transmittance, photoelectric conversion efficiency distribution, and side irradiation light responsiveness, a small and multifunctional sensor can be provided.

  The invention of claim 10, which has been made to solve the above problems, is the photosensor according to claim 1, wherein the photoelectric conversion region has at least one kind of electron-donating organic material, fullerenes and / or carbon nanotubes. It is characterized by comprising a mixture with an electron-accepting material containing, and a highly functional optical sensor can be easily produced by applying a mixed solution or the like.

  The invention of claim 11 made to solve the above-mentioned problem is an optical logic element characterized by using at least one photosensor of the invention of claims 1 to 10 and has a polarization response. By combining various types of optical sensors having characteristics, wavelength selectivity, light transmittance, photoelectric conversion efficiency distribution, and side irradiation light responsiveness, a small and thin optical logic element can be manufactured at low cost.

  The invention of claim 12 made to solve the above-mentioned problem is an electronic device using the optical sensor of claim 4 of the invention, wherein information is written at one wavelength, and information is written at a different wavelength. It is characterized by being capable of erasing, and it is possible to easily write and erase information simply by changing the wavelength of the light irradiating the electronic device. It becomes possible to provide.

  Hereinafter, embodiments of the optical sensor of the present invention will be described in detail.

  The substrate used in the optical sensor of the present invention is not particularly limited as long as it has mechanical and thermal strength and effectively transmits the irradiation light.

  For example, a material having high transparency in the visible light region such as glass, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, and fluorine resin should be used. The flexible substrate which has the flexibility which made these materials into a film may be sufficient. In the case of using a polymer material, it is also effective to provide a coating made of various metals, metal oxides, etc. on the outer surface of the substrate to the extent that the transmittance is not impaired as much as possible in order to improve its moisture resistance. is there.

  Further, depending on the application, a material that transmits only a specific wavelength, a material that converts light of a specific wavelength having a light-light conversion function, or the like may be used. Further, the substrate is preferably insulative, but is not particularly limited, and may have conductivity depending on a range that does not hinder the operation of the optical sensor or an application.

At least one of the electrodes of the optical sensor needs to transmit light, and this transmittance greatly affects the photoelectric conversion characteristics. Therefore, as the anode of the above-mentioned optical sensor, ITO, ATO (Sb-doped SnO ₂ ), AZO (Al-doped ZnO) or the like is generally called a transparent electrode formed by sputtering or ion beam evaporation. Things are used. In addition, by providing auxiliary electrodes, various metal material thin films such as Au and Ag, relatively high resistance coating type ITO, PEDOT (Poly (3,4-ethylene dioxy thiophene)), PPV (Poly (phenylene vinyl)), poly Various conductive polymer compounds such as fluorene can also be used.

  As the electron-donating organic material, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, diacetylene, and derivatives thereof are used. Moreover, it is not limited to a polymer, for example, porphyrin compounds such as porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, 1,1-bis {4- (di-P-tolylamino) phenyl } Cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetrakis (P-tolyl) -P-phenylenediamine, 1- (N, N-di-P— Tolylamino) naphthalene, 4,4′-bis (dimethylamino) -2-2′-dimethyltriphenylmethane, N, N, N ′, N′-tetraphenyl-4,4′-diaminobiphenyl, N, N ′ Aromatic tertiary compounds such as -diphenyl-N, N'-di-m-tolyl-4,4'-diaminobiphenyl, N-phenylcarbazole Stilbene compounds such as amines, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino) -4 ′-[4- (di-P-tolylamino) styryl] stilbene, triazole derivatives, oxa Diazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealed amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives Further, hydrazone derivatives, silazane derivatives, polysilane aniline copolymers, polymer oligomers, styrylamine compounds, aromatic dimethylidin compounds, poly-3-methylthiophene, and the like are also used.

As an electron-accepting material, fullerenes such as C60 and C70, carbon nanotubes, derivatives thereof, 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7) Oxadiazole derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives and the like.

  Any cathode can be used as long as the generated charge can be efficiently taken out to an external circuit. A metal such as Al, Au, Cr, Cu, In, Mg, Ni, Si, Ti, etc. Alternatively, Mg alloys such as Mg—Ag alloy and Mg—In alloy, Al alloys such as Al—Li alloy, Al—Sr alloy, and Al—Ba alloy are used. In order to improve the short circuit current, a method of introducing a metal oxide, a metal fluoride or the like between the organic layer and the cathode is also preferably used.

  As a manufacturing method when an organic photoelectric conversion element is manufactured using such a material, there are various vacuum processes such as a vacuum deposition method and a sputtering method, and wet processes such as a spin coating method and a dipping method. It may be possible, and it is possible to arbitrarily select a material suitable for the material, configuration, etc. to be used.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
An optical sensor according to Embodiment 1 of the present invention will be described.

  The element configuration is the same as that of the prior art shown in FIG.

  The optical sensor of the present invention is different from the conventional example in that the photoelectric conversion region 3 has a polarization response characteristic that can output different electrical signals according to the difference in the polarization plane of incident light. . In an optical sensor using an organic photoelectric conversion element, photoelectric conversion can be performed only when light is absorbed by the electron donating organic material. Therefore, if the electron donating material is uniaxially oriented and the moments of absorption are aligned, light that cannot be absorbed by the polarization plane can be generated, and a polarization response characteristic that outputs different electrical signals depending on the polarization plane of incident light is given. Is possible. A photoelectric conversion region formed of an electron-donating organic material made of a normal polymer material and the like and an electron-accepting material containing fullerenes and / or carbon nanotubes is formed by a spin coat method or the like, and thus formed photoelectric conversion. The region has an isotropic absorption characteristic, and the absorption characteristic is the same for light in any direction. However, by aligning the light absorption moment in one direction by uniaxially orienting this electron-donating organic material by rubbing or stretching, it is possible to absorb only light having the same plane of polarization as this absorption moment. .

  In order to effectively use this polarization response characteristic, it is preferable to set the current output Imax / Imin from the optical sensor to 2 or more, thereby improving the reliability of the optical switch using the difference in polarization plane, etc. An optical sensor with high detection reliability can be obtained.

(Embodiment 2)
An optical sensor according to Embodiment 2 of the present invention will be described.

  The element configuration is the same as that of the prior art shown in FIG.

  The optical sensor of the present invention is different from the conventional example in that the photoelectric conversion region absorbs light of a plurality of different wavelengths and can output different electric signals according to each wavelength, and each electric The signal is distinguishable.

  As described above, it has been difficult for conventional optical sensors to individually detect light in a plurality of wavelength regions using the same sensor. For this reason, in order to detect light in a plurality of wavelength regions, it is necessary to arrange optical sensors corresponding to the number of light beams, and there is a problem that space saving is hindered and cost is increased.

  The optical sensor of the present invention solves this problem, and detects light in different wavelength regions by controlling the absorption characteristics of the electron-donating organic material or, in some cases, mixing a plurality of electron-donating organic materials. It becomes possible. Furthermore, when a plurality of electron-donating organic materials having different absorption wavelengths are used, the open-end voltage changes according to the wavelength of the incident light. Therefore, it is possible to obtain an optical sensor that distinguishes incident light using this difference. .

  In addition, by using this optical sensor, it is possible to manufacture an electronic device that performs writing and erasing of information with a single element. For example, a signal that displays information by absorbing the wavelength α is output, an optical sensor that outputs a signal to be erased at the wavelength β is arranged in a matrix, and input instantaneously by combining with a display element having optical transparency, An information display device that can be erased can be provided. That is, when information is written on the information input display device using a writing means capable of emitting light of wavelength α to the information display device, the light sensor can detect the light and display the information, and then display the wavelength. When information on the information display device is traced using an erasing means capable of emitting β light, the light sensor can detect the light and erase the information. As described above, if one optical sensor can separately detect light of different wavelengths, the number of optical sensors to be arranged can be reduced, so that a high-definition information display device can be provided.

(Embodiment 3)
An optical sensor according to Embodiment 3 of the present invention will be described.

  FIG. 1 is a cross-sectional view of a main part of an optical sensor according to Embodiment 3 of the present invention. In FIG. 1, the configuration of the substrate 1, the electrode 2, the photoelectric conversion region 3, and the cathode 6 is the same as that of the conventional example.

  The optical sensor of the present invention is different from the conventional example in that a part of the optical sensor transmits light and / or has a light transmission part 22 that can detect light and output an electric signal. It is a point. Many of the materials forming the organic photoelectric conversion element have light transmittance. In a normal element, only a cathode using a metal material has no light transmission, but this cathode also provides light transmission by using a metal ultra-thin film of about 10 nm or indium oxide (ITO). By using such a cathode, it is possible to form a light transmissive optical sensor having the light transmissive portion 22. If such a light-transmitting optical sensor is used, a part of the light can be absorbed and the remaining light can be transmitted in order to detect the light, and the light can be effectively used. In the present embodiment, the case where a part of the optical sensor is the light transmitting portion 22 has been described. However, there is no problem even if the entire optical sensor transmits light.

  Further, if such a light transmissive optical sensor is used, it is possible to reduce the size of an image sensor that has been widely used. As described above, in the conventional image sensor shown in FIG. 6, since the light receiving portion does not have light transmittance, it is necessary to arrange the light source obliquely with respect to the light receiving portion and irradiate the original. For this reason, the light receiving unit and the original are inevitably separated from each other, and various optical systems such as a SELFOC lens are necessary to maintain the resolution. Due to such a configuration, the conventional image sensor is larger than necessary.

  However, if the light-transmitting optical sensor in the third embodiment is used, a light source and a light receiving unit are stacked, the original is irradiated through the light receiving unit, and the reflected light from the original is read by the light receiving unit. An image sensor can be realized.

FIG. 2 is a cross-sectional view of an essential part of an image sensor using the optical sensor according to Embodiment 3 of the present invention. Here, 11 is a substrate, 12 is a light source, 13 is an optical sensor, and 14 is a document. By using the light-transmitting optical sensor 13 in this way, the light source 12 and the optical sensor 13 can be stacked. In some cases, the SELFOC lens 8 or the like is not required, and thus the size and thickness can be significantly reduced. become.

(Embodiment 4)
An optical sensor according to Embodiment 4 of the present invention will be described.

  The element configuration is the same as that of the prior art shown in FIG.

  The optical sensor of the present invention is different from the conventional example in that the photoelectric conversion efficiency is distributed within the same sensor. Accordingly, it is possible to determine which part of the sensor is irradiated with light based on the strength of the electrical signal output from the optical sensor. For example, when the sensor is fabricated such that the center of the sensor has the highest conversion efficiency and the conversion efficiency decreases with increasing distance from the center, the deviation from the center of the incident light can be detected as the attenuation of the electrical signal. Such a distribution of conversion efficiency can be realized by a method of giving a distribution to the transmittance of the substrate and the film thickness of the photoelectric conversion region. In addition, the distribution of photoelectric conversion efficiency in the present invention refers to what is intentionally created, and does not include the case where distribution in the photoelectric conversion efficiency is unavoidable due to variations in device fabrication.

(Embodiment 5)
An optical sensor according to Embodiment 5 of the present invention will be described.

  The element configuration is the same as that of the prior art shown in FIG.

  The optical sensor of the present invention is different from the conventional example in that it detects the light irradiated from the side portion with respect to the stacking direction of the electrode and the photoelectric conversion region. In an ordinary optical sensor, incident light first reaches the photoelectric conversion region after passing through the substrate and the electrode. For this reason, light loss due to absorption of the substrate and electrodes cannot be prevented, and there is a limit to miniaturization of each component such as electrodes and photoelectric conversion regions. However, the optical sensor of the present invention can solve these problems by irradiating light from the side with respect to the stacking direction of each component at the time of device fabrication.

  This can be realized, for example, by using a layer in which an anode, a photoelectric conversion region, and a cathode are stacked in this order on a substrate in the same manner as a normal optical sensor and irradiating light from the side. As a result, the incident light directly reaches the photoelectric conversion region and can generate a photovoltaic force. In particular, in the case of the optical sensor having such a configuration, the electrodes need not be light transmissive, and all the electrodes can be formed of a metal material having high reflectance. Furthermore, by using this optical sensor, it is possible to arrange RGB optical sensors at a narrow pitch.

(Embodiment 6)
An optical sensor according to Embodiment 6 of the present invention will be described.

  The element configuration is the same as that of the prior art shown in FIG.

  The optical sensor of the present invention is different from the conventional example in that one sensor has a plurality of functions among polarization response characteristics, multiple wavelength responsiveness, light transmission, photoelectric conversion efficiency distribution, and lateral illumination light responsiveness. It is a point. Thereby, a small and multifunctional optical sensor can be obtained. For example, in a sensor having both polarization response characteristics and light transmission, it becomes possible to check the deviation of the polarization plane in the middle of the optical path, and in a sensor having both multi-wavelength response and light transmission, light of a wavelength that does not respond. Once transmitted, the light can be used for other applications. Thus, by providing a plurality of functions to one sensor, it is possible to provide a sensor that effectively uses light, instead of a conventional sensor that merely detects light.

(Embodiment 7)
An optical sensor according to Embodiment 7 of the present invention will be described.

  FIG. 3 is a cross-sectional view of a main part of an optical sensor according to Embodiment 7 of the present invention. In FIG. 3, the configuration of the substrate 1, the anode 2, and the cathode 6 is the same as the conventional example.

  The optical sensor of the seventh embodiment is different from the conventional one in that the photoelectric conversion region of the optical sensor having polarization response characteristics, multiple wavelength response characteristics, light transmittance, photoelectric conversion efficiency distribution, side irradiation light response characteristics, etc. Reference numeral 17 denotes a point made of a mixture of an electron accepting material 16 containing fullerenes and / or carbon nanotubes and an electron donating organic material 15.

  Here, “mixing” refers to a state where liquid or solid materials are mixed in a container and, if necessary, added with a solvent and stirred to form a mixture by spin coating or the like. Also includes membranes.

  Such a mixed-type optical sensor absorbs light, excites, and exchanges electrons throughout the photoelectric conversion region 17 and exhibits a relatively high conversion efficiency while having a very simple structure. It is also possible to provide an optical sensor with improved efficiency.

(Embodiment 8)
An optical logic element according to Embodiment 8 of the present invention will be described.

  The optical logic element of the present invention uses at least one of the polarization response characteristics, wavelength selectivity, light transmittance, photoelectric conversion efficiency distribution, side irradiation light response characteristics described in the first to fourth embodiments, or a combination of these. This makes it possible to output different signals depending on the optical input to the element. For example, when using an optical sensor that responds to two wavelengths and generates different outputs, outputs of AND, OR, etc. are obtained depending on whether one or two light beams with the corresponding wavelength are emitted. Can do. In addition, in the case where the optical sensor to be used has optical transparency, it is possible to design a more complicated logic circuit by stacking the optical sensors.

(Embodiment 9)
An electronic device according to Embodiment 9 of the present invention will be described.

  4A and 4B are plan views of an electronic device in which an optical sensor and a display element are combined.

  In FIG. 4A, 18 is a writing optical sensor, 19 is an erasing optical sensor, and 20 is a display element. In this electronic device, the writing light beam irradiated from the information writing means is detected by the writing light sensor 18 after passing through the display element 20, and the corresponding pixel of the display element 20 is turned on based on this information. Thereby, arbitrary handwritten information can be displayed on the display element 20. When erasing this information, the erasing optical sensor 19 is irradiated with light from the information erasing means as in the case of writing.

Although it is possible to provide an information display device that supports handwriting input by the electronic device as described above, it is necessary to separately arrange two sensors for writing and erasing, which causes a problem in high definition. is there. Therefore, in the electronic device of the present embodiment, as shown in FIG. 4B, an optical sensor that can absorb light of a plurality of different wavelengths and output different electrical signals according to each wavelength is used. Yes. In FIG. 4B, reference numeral 21 denotes a two-wavelength response sensor capable of individually responding to two different wavelengths. Since this two-wavelength response sensor 21 can individually respond to two types of light of writing and erasing with one sensor, the number of sensors can be reduced to half and the light receiving area can be reduced. It is possible to cope with high definition including the display element 20.

  An ITO film having a film thickness of 150 nm is formed on a glass substrate by sputtering, and a resist material (manufactured by Tokyo Ohka Kogyo Co., Ltd., OFPR-800) is applied on the ITO film by spin coating to form a resist film having a thickness of 5 μm. The resist was patterned into a predetermined shape by masking, exposing and developing. Next, this glass substrate is immersed in an aqueous hydrochloric acid solution of 18N at 60 ° C., the ITO film where the resist film is not formed is etched, washed with water, and finally the resist film is removed to remove the ITO film of a predetermined pattern. A glass substrate having a first electrode made of a film was obtained.

  Next, these glass substrates were subjected to ultrasonic cleaning for 5 minutes with detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, and hydrogen peroxide against 1 ammonia (volume ratio). After 5 minutes of ultrasonic cleaning with a mixture of water 1 and 5 and 5 minutes of ultrasonic cleaning with pure water at 70 ° C., water attached to the glass substrate is removed with a nitrogen blower. Heat to 250 ° C. to dry.

  Subsequently, poly (3,4) ethylenedioxythiophene / polystyrene sulfonate (PEDT / PSS) was dropped on the substrate through a 0.45 μm filter and uniformly applied by spin coating. This was heated in a clean oven at 200 ° C. for 10 minutes to form a buffer layer.

  Next, poly (2-methoxy-5- (2′-ethylhexyloxy) -1,4-phenylenevinylene) (MEH-PPV) and [5,6] -phenyl C61 butyric acid methyl ester ([5,6 ] -PCBM) 1: 4 chlorobenzene solution was formed using the vertical spin coating method so that the solution was spread in only one direction in the substrate, and then heated in a clean oven at 100 ° C. for 30 minutes. By processing, a photoelectric conversion region of about 100 nm oriented in one direction was formed.

Finally, the film thickness of LiF is about 1 nm, and then Al is about 100 nm in a resistance heating vapor deposition apparatus whose pressure is reduced to 0.27 mPa (= 2 × 10 ⁻⁶ Torr) or less above the photoelectric conversion region. The optical sensor having a polarization response characteristic was obtained.

  When this optical sensor was irradiated with polarized light, Imax / Imin = 3, and it was confirmed that it had a polarization response characteristic in which the electrical output changes according to the rotation of the polarization plane.

After the buffer layer was formed in the same manner as in Example 1, poly (2-methoxy-5- (2′-ethylhexyloxy) -1,4-phenylenevinylene) (MEH-PPV) and [5,6] -phenyl A chlorobenzene solution of C61 butyric acid methyl ester ([5,6] -PCBM) in a weight ratio of 1: 4 was applied by an ordinary spin coating method to form a photoelectric conversion region of about 100 nm. On top of this, LiF is deposited to a thickness of about 1 nm and then Au is deposited to a thickness of about 10 nm in a resistance heating vapor deposition apparatus depressurized to a vacuum of 0.27 mPa (= 2 × 10 ⁻⁶ Torr) or less. A transparent optical sensor was obtained. At this time, the light transmittance of the element portion was about 30% around 500 nm. When this optical sensor was irradiated with a second harmonic wave (532 nm) of an Nd-YAG laser, a photoelectromotive force was generated in the sensor part, and the remaining light passed through the element part and came out from the back surface, and thus the optical transparency. It was confirmed that the optical sensor was completed.

  The optical sensor according to the present invention has polarization response characteristics, multiple wavelength responsiveness, light transmittance, photoelectric conversion efficiency distribution, and lateral illumination light responsiveness, and is used for various position detection, optical communication, and optical logic elements. It is useful as an optical sensor.

Sectional drawing of the principal part of the optical sensor in Embodiment 3 of this invention Sectional drawing of the principal part of the image sensor using the optical sensor in Embodiment 3 of this invention Sectional drawing of the principal part of the optical sensor in Embodiment 7 of this invention (A), (b) is a top view of the electronic device which combined the optical sensor and display element in Embodiment 9 of this invention Cross section of the main part of a typical organic photoelectric conversion device Cross section of the main part of a conventional image sensor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Photoelectric conversion area 4 Electron donating layer 5 Electron accepting layer 6 Cathode 7 Light source 8 Selfoc lens 9 Optical sensor 10 Original 11 Substrate 12 Light source 13 Optical sensor 14 Original 15 Electron donating organic material 16 Electron accepting Material 17 Photoelectric conversion region 18 Optical sensor for writing 19 Optical sensor for erasing 20 Display element 21 Two-wavelength response sensor 22 Light transmitting portion

Claims (12)

A photoelectric conversion region comprising at least two electrodes on the substrate, at least one electron-donating organic material between the electrodes, and an electron-accepting material including fullerenes and / or carbon nanotubes; An optical sensor characterized by having a polarization response characteristic that outputs different electrical signals according to the difference in polarization plane. 2. The optical sensor according to claim 1, wherein Imax / Imin is 2 or more, where Imax is a maximum value of current output from the optical sensor having the polarization response characteristic and Imin is a minimum value. 3. The photosensor according to claim 1, wherein an electron donating organic material is oriented in the photoelectric conversion region. A photoelectric conversion region comprising at least two electrodes on the substrate, at least one electron-donating organic material between the electrodes, and an electron-accepting material including fullerenes and / or carbon nanotubes; An optical sensor characterized in that it can absorb light of different wavelengths and output different electrical signals according to each wavelength, and that each electrical signal can be distinguished. An optical sensor having a photoelectric conversion region comprising at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, and an electron accepting material containing fullerenes and / or carbon nanotubes. An optical sensor characterized in that at least a part of the optical sensor is light transmissive. An optical sensor having a photoelectric conversion region comprising at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, and an electron accepting material containing fullerenes and / or carbon nanotubes. The photoelectric conversion efficiency of the optical sensor has a distribution within the same sensor. The optical sensor according to claim 6, wherein the distribution of the photoelectric conversion efficiency changes from the center of the sensor toward the outside. An optical sensor having a photoelectric conversion region comprising at least two electrodes on a substrate, at least one electron donating organic material between the electrodes, and an electron accepting material containing fullerenes and / or carbon nanotubes. An optical sensor, wherein a side portion of the electrode and the photoelectric conversion region with respect to the stacking direction is a light receiving portion. An optical sensor having at least two of the functions of the optical sensor according to claim 1. 10. The optical sensor according to claim 1, wherein the photoelectric conversion region is made of a mixture of at least one electron donating organic material and an electron accepting material containing fullerenes and / or carbon nanotubes. Features an optical sensor. An optical logic element using at least one optical sensor according to claim 1. 5. An electronic device using the optical sensor according to claim 4, further comprising means for writing information at one wavelength and erasing information at a different wavelength.

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