KR20020066321A - Encapsulation of organic electronic devices - Google Patents

Abstract

The use of an airtight enclosure containing a porous desiccant prevents the moisture and oxygen of the atmosphere from reaching the materials used to manufacture the device, thereby preventing the moisture and oxygen of the atmosphere from adversely affecting the performance of the device. .

Description

ENCAPSULATION OF ORGANIC ELECTRONIC DEVICES}

Solid state electronic devices made from composite organic polymer layers have attracted attention. Composite polymer based diodes, in particular light emitting diodes and photosensitive diodes, have received particular attention due to their potential in display and sensor technology. All references, patents, and patent applications referred to herein are referenced as well as these references.

An apparatus of this kind has a structure comprising a layer or film of electrophotoactive composite organic polymer bounded on opposite sides by electrodes (anode and cathode) and supported on a solid substrate.

In total, materials for use as active layers in polymer diodes and in particular light emitting diodes include semiconducting composite polymers, such as semiconducting composite polymers that exhibit photoluminescence. In any preferred setting, the polymer is a semiconducting composite polymer that exhibits photoluminescence and can be dissolved into a uniform thin film from solution.

The anodes of such organic polymer based electronic devices typically consist of relatively high work function metals and transparent non-stoichiometric semiconductors such as indium / tin oxides. These anodes function to inject holes into other filled pi-bands of semiconducting, luminescent polymers.

In various structures relatively high work function metals, such as barium or calcium, are preferred as cathode materials. Such low work function metals and ultra thin layers of these oxides are preferred. These low work function cathodes function to inject electrons into other empty pie bands of semiconducting, light emitting polymers. Holes injected into the anode and electrons injected into the cathode radially recombine in the active layer to emit light.

Unfortunately, although the use of low work function materials is required for the effective injection of electrons from the cathode and the performance of satisfactory devices, low work function metals such as calcium, barium and strontium and their oxides usually react chemically well. They easily react with oxygen and water vapor at room temperature and more vigorously at elevated temperatures. This reaction destroys the required low work function properties and degrades the critical interface between the cathode material and the luminescent semiconducting polymer. This creates a persistent problem that causes a rapid drop in device efficiency (and light output) during storage and especially under elevated temperatures.

Other organic polymer based solid state devices also present similar stability issues. The components of the photosensitive device and device array and the materials used therein are very similar to those found in polymer based light emitting diodes. The main difference between polymer-based light-emitting diodes and photodetectors is that an extremely responsive low work function electrode does not have to be used and the electrical polarity of the electrode often changes. Nevertheless, moisture and oxygen react with the components in the device and, over time, lead to a decrease in device performance.

One solution to minimizing the deleterious effects of atmospheric exposure is to enclose the device in a barrier that separates the active material from oxygen and moisture. While this solution has some effect, it does not always adequately solve the problem caused by the small amount of moisture that is confined within the skin or diffuses into the skin over time.

U. S. Patent No. 5,588, 761 to Kawami et al. Discloses a method for packaging a light emitting device manufactured using a thin film of luminescent organic molecules as an active layer to solve the problem of moisture contamination. This patent describes the installation of a water reactive solid component, such as sodium oxide, in the enclosure for the device. These reactive components covalently react with water in the skin to transform the water into a solid product. For example, sodium oxide reacts vigorously with moisture to yield solid sodium hydroxide. This patent describes employing a moisture reactive component that removes moisture to retain moisture at high temperatures. It should be noted that in the patents of Kawami et al., Since moisture is discharged at a high temperature (for example, 85 ° C.), a material that physically absorbs moisture cannot be used.

In Kawami's patent, the solid component that reacts with water itself reacts well and similarly produces highly reactive reaction products. Thus, any accidental contact between these components or the reaction product with other components within the device or device envelope can be harmful. Thus, there is a need for a method of sealing encapsulation of an organic polymer based solid state electronic device, which is sufficient to prevent water vapor and oxygen from diffusing into the device and thereby limiting its practical lifetime.

In addition, many well known processes for forming hermetically sealed capsules of electronic devices require the device to be heated to a temperature in excess of 300 ° C. during the capsule sealing process. Most polymer based release devices are not suitable at these high temperatures.

The present invention relates to organic polymer based electronic devices such as diodes, for example light emitting diodes and photosensitive diodes. More specifically, the present invention relates to manufacturing processes and structures for devices that lead to high device efficiency and have a commercially satisfactory long operating life.

1 is a schematic cross-sectional view of a representative apparatus of the present invention.

FIG. 2 is a graph showing the effect of various desiccant materials on encapsulated devices by comparing their lifetime at 85 ° C. under atmospheric humidity conditions.

3 is a series of graphs comparing the effect of water removal according to the present invention with water removal using prior art materials and methods.

Figure 4 is a graph comparing the stability of the prior art method and the water removal method of the present invention.

The present invention relates to a hermetic shell, porous structure having a polymer electronic device comprising a pair of electrodes facing each other and an active polymer layer sandwiched between the electrodes, an inner surface adjacent to the polymer electronic device and an opposite outer surface adjacent to the outer atmosphere. And to trap moisture by physically absorbing moisture in the porous structure, and to an electronic device containing a desiccant adjacent to an inner surface, wherein the hermetic envelope is a polymer to isolate the polymer electronic device and the desiccant from the outside atmosphere. Encapsulate the electronic device. The present invention also relates to a method of making a polymer electronic device having an improved lifetime by encapsulating the polymer electronic device in an airtight shell with a solid desiccant.

In a preferred embodiment, the desiccant is incorporated into one or more substrate layers that support the polymer electronic device.

As used herein, the term "adjacent" does not necessarily mean that one layer is immediately after the other, but with a second surface (eg, an outer surface) opposite the first surface. In comparison, the position is closer to the first surface (eg, the desiccant is closer to the inner surface).

As best seen in FIG. 1, the electronic device 100 of the present invention is a polymer electronic device 110 that includes an anode 112 and an anode 114 with electrical attachment leads 116, 118, electrically; An active organic polymer 120 layer and, in the presently preferred embodiment, a substrate 122. Device 110 also includes an encapsulation envelope 124 that isolates the electronic device from the atmosphere. The sheath is made of substrate 122 as a base with a cover or lid 126 attached to base 122 by adhesive 128. Desiccant 130 is encapsulated within sheath 124 and is preferably attached to the interior surface 132 of the sheath with adhesive 134.

Board

Substrate 122 is generally impermeable to gas and moisture. In a preferred embodiment the substrate is glass. In a second preferred embodiment, the substrate is silicon. In a third preferred embodiment, the substrate is a flexible substrate, such as a composite material composed of an impermeable plastic or a combination of inorganic and plastic materials. Examples of useful flexible substrates include sheets or multiple laminates of a flexible material of an impermeable plastic, such as polyethylene terephthalate, or a plastic sheet having a precipitated selective metal or inorganic dielectric layer. Composite materials composed of combinations. In a preferred embodiment, the substrate is transparent (or translucent) such that light can enter or escape from the encapsulated area.

coat

Hermetic envelope 126 isolates polymer electronic device 110 from the atmosphere. The manner in which the hermetic envelope is formed is not critical, unless the process steps have a deleterious effect on the components of the polymer electronic device 110. For example, hermetic envelope 126 may be formed of multiple pieces bonded together with an adhesive. In a preferred embodiment, the hermetic shell includes a lead 126 bonded to the base. As best shown in FIG. 1, a good base 122 is the substrate of the polymer electronic device 110.

The material used to form the hermetic shell 126 should be impermeable to gas and moisture. In one embodiment, the leads are made of metal. In another embodiment, the lead is made of glass or ceramic material. Plastics that are air impermeable and moisture impermeable may also be used.

If the lid 126 is thick enough to be a continuous blocking portion (no gaps or pin holes), the thickness of the lid 126 is not critical to the present invention. Preferably, the lid 126 has a thickness between about 10 and about 1000 μm. If the base is not a substrate of a polymer electronic device (not shown), it can be seen that the base cannot be made of the same material as the lead. As best shown in FIG. 1, the lid 126 is sealed to the substrate 122 by an adhesive 128. The adhesive should be cured at temperatures below 75 ° C., preferably below 50 ° C. and more preferably below the decomposition temperature of the active layer 120, such as at ambient or moderately elevated temperatures. This is often beneficial because it eliminates exposure to high temperatures that are common in the art, which can damage or degrade the electronic device 110. Preferred adhesives include epoxies that cure by either (or both) exposure to ultraviolet light or exposure to the moderately elevated temperatures just mentioned. Various main materials (not shown) may be used to assist the adhesion process. As best shown in Figure 1, electrical leads 116, 118 exit from the device. These leads 116, 118 should likewise be sealed by adhesive 128. Alternatively, however, functionally equivalent conductor structures may be used.

Solid desiccant

Before sealing the lid 126 on the substrate 122 and surrounding the electronic device 110, a solid desiccant (drying material) 130 is inserted. The form in which the desiccant is included is not critical. For example, desiccant 130 may be in the form of a powder in a porous packet, a compressed pallet, a solid embedded in a gel, a solid embedded in a cross-linked polymer, and / or a membrane. Desiccant may be located in sheath 124 in a variety of ways. For example, the desiccant 130 may be incorporated into a coating on the inner surface of the substrate or lid (not shown), and as best seen in FIG. 1, the desiccant 130 may be enveloped 124 with an adhesive 134. It may be provided by attaching to the inner surface 132 of the). Alternatively (not shown), the desiccant may be incorporated into a flexible substrate of the electronic device or one or more multilayer or stacked substrates.

The properties of the solid desiccant are important. Most commonly, porous solids are mostly inorganic solids with controlled pore structures that allow water molecules to migrate but physically absorb the water molecules so that they are trapped and not released to the surroundings in the shell. Molecular sieve is one such material. In a preferred embodiment, the desiccant encapsulated in a sealed package is zeolite. Zeolites are well known materials and are commercially available. In total, any zeolite suitable for confining moisture may be used. Zeolites are known to consist of approximately the same amount of aluminum and silicon oxide as sodium as counter ions. Zeolite materials absorb moisture by physical absorption rather than chemical reactions. Physical absorption is preferred.

In a more preferred embodiment, the desiccant 130 encapsulated in the shell 124 is tri-sorb (United Catalysts Ink.), Beren, Beren, Mexico. Zeolite material, a member of the Sued-Chemie group, available from Sued-Chemie Performance Packaging. The trisorb structure contains about the same amount of aluminum and silicon oxide as sodium as the counter ion. Trisorb absorbs moisture by physical absorption. Notable improvements in the stability and lifetime of the encapsulated polymer light emitting diodes according to the methods described herein are described in the examples. In particular, encapsulation using physically absorbing zeolite materials as desiccant is much better as desiccant than barium oxide, which absorbs moisture by chemical absorption.

The amount of desiccant added should be determined to provide a suitable capacity to absorb the moisture trapped in the shell when it is closed and closed. The desiccant's ability to suck moisture is a well known attribute. The internal volume of the device and the air humidity in the enclosure can be readily determined. These factors can be determined and associated in consideration of the appropriate weight of the desiccant.

In a preferred embodiment, more than a calculated amount of desiccant may be added to counteract the residual flow of water vapor in the active device region through incomplete edge sealing and / or residual transmission of water vapor through the substrate.

Active layer

Among the materials for use as the active layer 120 in electronic devices protected by the present invention, such as polymer light emitting diodes, are poly [poly, phenylene vinylene], PPV, and, for example, poly {2- Methoxy-5- (2'ethyl-hexoxyoxy) -1,4-phenylene vinylene [2-methyoxy-5- (2'-ethyl-hexyloxy) -1,4-pheny lene vinylen]}, MEH- There are soluble derivatives of PPV, such as PPV, semiconducting polymers with energy gaps (eg, 2.1 eV or more). Such materials are described in more detail in US Pat. No. 5,189,136. Other materials described as useful in the present invention include poly {2,5-bis (cholestanoxy-1,4-phenylene vinylene)}, BCHA -PPV, semiconducting polymers with energy gaps (e.g., 2.2 eV or more) Such materials are described in more detail in US Patent Application No. 07 / 800,555. Other suitable polymers are, for example, J. Appl. Phys. 72,564 (1992) by D. Braun, G. Gustafsson, D. McBranch and AJ Heeger. Poly [3-alkylthiophenes and M. Berggren, O. Inganas, G. Gustafsson, J. Rasmusson. Related derivatives described by Rasmusson, MR Andersson, T. Hjertberg and O. Wennerstrom; G. Grem, G. G. Leditzky, Poly [paraphenylene] as described in Adv. Mater. 4, 36 (1992) by B. Ullrich and G. Leising, and Z. Yang, Ai. I. Sokolik, soluble derivative described in Macromolecules, 26, 1188 (1993) by FE Karasz, J. Appl. Phys, Appl. By ID Parker Polysquinoline, described in Phys. Lett. 65, 1272 (1994.) Also, mixtures of complex semiconducting polymers in non-composite main polymers can be found in C. Zhang, H. von S. H. Von Seggern, K. Parkbach Pakbaz), B. B. Kraabel, H. Double You. H.W. Schmidt and A.J. Synth. By A.J. Heeger. It is useful as an active layer in the polymer light emitting diode described in Met, 62,35 (1994). Also H. N. Nishino, G. G. Yu, T-A. T-A. Chen, R. D. R.D. Rieke and A.J. Synth. By A.J. Heeger. Also useful are mixtures comprising two or more composite polymers described in Met., 48,243 (1995). Overall, materials for use as active layers in polymer light emitting diodes are semiconducting composite polymers, specifically semiconducting composite polymers that exhibit photoluminescence, and more specifically semiconducting composite polymers that are soluble and processable in solution into thin films.

High work function anode

A relatively high work function metal suitable for use as the anode material 112 is a thin film of transparent indium / tin conductive oxide. H. Burroughs, D.C. Bradley, A. D.D.C. egg. A.R. Brown, R.N. Marks, K. K. Mackay, R. H. R.H. Frend, P. L. Nature 347,539 (1990) by P.L. Burns and A.B. Holmes; D. Brown and D. Braun. Appl. Of A.J. Heeger. Phys. Lett. 58, 1982 (1991). Alternatively, a thin film of conductive polymer may be used. G. Gustafsson, Y. Y. Cao, G. M. G.M. Treacy, F. F. Klavetter, N. N. Colaneri and A.J. Nature, A. J. Heeger, 357, 477 (1992), Y. Y. Yang and A.J. Appl. Of A.J. Heeger. Phys. Lett 64,1245 (1994) and US patent application Ser. No. 08 / 205,519, Y. Yang, Yi. Westerweele, poetry. C. Zhang, P. Smith and A. J. Appl. Of A.J. Heeger. Phys. 77,694 (1995), J. Gao, A.J. Heeger, J.W. J.Y. Lee and S.Y. Synth. Of C.Y Kim. Met., 82,221 (1996), Y. Y. Cao, G. G. Yu, poetry. C. Zhang, R. Menon and A.J. Appl. Of A.J. Heeger. Phys. Lett. May be used as specified in 70,3191 (1997). Two layers of anodes, including an indium / tin oxide thin film and a polyaniline thin film in the form of a conductive emeraldine salt, allow both materials to emit light emitted from the light emitting diode from the device at useful levels. It is preferable as a transparent electrode.

Low work function cathode

Suitable relatively low work function metals for use as the cathode 114 material include alkaline earth metals such as calcium, barium, strontium and ash earth metals such as ytterbium. Also, for example, alloys of low work function metals such as alloys of magnesium in silver and lithium alloys in aluminum are known from the prior art (US Pat. Nos. 5,047,687, 5,059,862 and 5,408,109). The thickness of the electron injection cathode layer is described in the prior art [US Pat. No. 5,151,629, US Pat. No. 5,247,190, US Pat. No. 5,317,169 and J. Pat. J. Kido, H. H. Shionoya, K. Appl. By K. Nagai. Phys. Lett., 67 (1995) 2281, in the range from 200 to 5000 mm 3. The lower limit of 200 to 500 Angstroms is the cathode layer [US Pat. No. 5,512,654; J. City. Scott, J. H. J.H. Kaufman, P. J. B. Brock, R. R. Dipietro, J. Salem and J. A. J. Appl. Of J.A. Goitia. Phys., 79 (7996) 2745; ID. Parker, H.H. Kim, Appl. Phys. Lett., 64 (1994) 1774). For further good protection, the thicker cathode layer is believed to provide a self-sealing bond that keeps oxygen and water away from the active portion of the device.

Electron injection cathodes comprising ultra thin layers of alkaline earth metals, calcium, strontium and barium have been described for high brightness and high efficiency polymer light emitting diodes. Compared with conventional cathodes made of the same metal (and other low work function metals) as a film having a thickness greater than 200 mW, the cathode comprising an ultrathin layer alkaline earth metal having a thickness of less than 100 mW is a polymer light emitting diode [Wi]. . Y. Cao and G. US Patent Application No. 08 / 872,657 to G. YU improves the stability and operating life.

In addition, electron injection cathodes comprising ultra thin layers of oxides of alkaline earth metals, calcium, strontium and barium have been described for high brightness and high efficiency polymer light emitting diodes (Y. Cao et al., Oct. 12, 1999). PCT Application No. US99 / 23775, filed date.

The components of the photosensitive device and device array and the materials used therein are very similar to the manufacture of polymer based light emitting diodes. The main difference between polymer-based light-emitting diodes and photodetectors is that a low-response low work function electrode does not have to be used and the electrical polarity of the electrode changes. Nevertheless, a hermetically sealed package is required to extend the life of a photosensitive device made from a conductive polymer. Thus, the encapsulation envelope of the present invention is useful in such devices as well, and the encapsulation is sufficient to prevent water vapor and oxygen from diffusing into the device, thereby limiting its practical lifetime.

The invention will be explained in more detail with reference to the following examples. These examples are provided only to illustrate various modes of practicing the invention and should not be construed as limiting the scope of the invention.

Example 1

Zeolite based desiccants (tri-sorb) are used as drying agents or desiccants. As an example of a polymer based electronic device, a polymer light emitting diode array is used.

Air and moisture impermeable reeds made of glass containing dry tablets containing zeolites (from the Sued-Chemie Group, United Catalysts Ink., Beren, NM) Member, available from Sued-Chemie Performance Packaging, is used to isolate from the atmosphere by encapsulating a light emitting diode array.

The desiccant uses an thermosetting epoxy resin (Araldite 2014 of Ciba Specialty Chemicals Corp., East Lansing, Mich.) As an adhesive to the inner surface of the impermeable lead. It is enclosed in a package by fixing a desiccant on the bed.

Desiccants are in the form of compacted pellets of powder. The impervious lead is attached to the substrate using an adhesive. The completed device has the structure 100 shown in FIG. The lid is sealed to a glass substrate, using Araldite 2014 as the adhesive.

Immediately after sealing the package, the dimensions of the light emitting pixels are measured. The package device is then placed for a period of time extending in an oven at 85 ° C. of atmospheric humidity. Every 50 hours, the device is removed from the oven and the dimensions of the light emitting pixels are measured again. The degradation of the polymer electronics due to humidity and oxygen is measured by the reduction of the active area. In this particular embodiment, the reduction of the light emitting area for the pixelated light emitting diode display is measured. As can be seen from FIG. 2, the trisorb desiccant results in a reduction of the emission area of less than 2% after 300 hours of storage at 85 ° C.

In addition, as can be seen in FIG. 2, the zeolite base desiccant (in this case, as a specific example, trisobra proceeds as a branded product) is another example of barium monoxide (BaO) and calcium sulfate; Such desiccant materials are significantly better than the already known useful desiccant materials (US Pat. No. 5,882,76). This example shows that zeolite desiccants can be effective desiccants even at high temperatures.

Example 2

The experiment of Example 1 is repeated except that the storage conditions are adjusted to include high humidity, for example a relative humidity of 85 ° C./85%. As can be seen in FIG. 3, the polymer light emitting diode array shows a reduction in emission area of less than 5% after 300 hours.

Also, as can be seen from FIG. 3, the zeolite system is superior to various other desiccants including barium monoxide or calcium monoxide (such desiccant materials are patented as effective desiccant materials (US Pat. No. 5,885,761)).

This example shows that the zeolite base desiccant is a very effective desiccant even in high temperature, high humidity environments.

Example 3

The experiment of Example 1 is repeated except that the form of the desiccant is a powder embedded in a porous packet fixed on the inner surface of the impermeable lead by the use of an adhesive. The reduction of the emission area can be compared with the data shown in FIGS. 2 and 3.

This example shows that the specific physical shape of the desiccant is not critical.

Example 4

A weight loss study of thermogravimetric measurements is performed on Trisorb and barium monoxide is compared to its performance in permanently removing moisture from the electronic device envelope. A standard, calibrated thermogravimetric facility is used. While the mass of the tablet is continuously monitored, the tablet of trisorb and barium monoxide is heated in a dry atmosphere (from room temperature to 400 ° C.). Hysteresis was not found.

The results are shown in FIG. At room temperature both samples absorb moisture. As heated, both release moisture due to the thermodynamic process and the reduction in sample weight. However, as can be seen, trisorb releases less moisture. At 85 ° C., the Trisorb sample releases three times less moisture than the barium monoxide sample. This example shows that trisorb has better material properties than barium monoxide (patented as a good desiccant at 85 ° C.) at high temperatures.

As can be seen by the foregoing description, the present invention provides a technique for encapsulating a polymer light emitting device at the lowest possible temperature. The method of encapsulation provides a hermetic seal between the device and atmospheric air with harmful moisture and oxygen. In addition, the present method for encapsulation ensures that the overall thickness of the device is not significantly increased by the encapsulation of the device. In addition, the present encapsulation method requires a smaller individual process than other methods known in the art.

Claims (26)

A polymer electronic device 110 comprising a pair of electrodes 112 and 114 facing each other and an active polymer layer 120 sandwiched between the electrodes, Hermetic envelope 124 having an inner surface 132 adjacent to the polymer electronic device and an opposite outer surface adjacent to the outer atmosphere, A desiccant 130 adjacent the inner surface, The desiccant has a porous structure and can trap moisture by physically absorbing moisture into the porous structure, wherein the hermetic envelope encapsulates the polymer electronic device and the polymer electronic device to isolate the desiccant from the external atmosphere. Device. A method of manufacturing a long life organic polymer based electronic device, Providing a polymer electronic device 110 having a pair of electrodes 112 and 114 facing each other and an active polymer layer 120 sandwiched between the electrodes, The polymer electronic device is encapsulated in an hermetic sheath 124 in combination with a solid desiccant 130 having a porous structure capable of trapping moisture by completely absorbing moisture into the porous structure, the envelope encapsulating the device and desiccant from the external atmosphere. Sequestering said method. 3. The electronic device and / or of claim 1, wherein the polymer electronic device comprises a substrate comprising one or more substrate layers such that the solid desiccant is incorporated into one or more of the one or more substrate layers. Way. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is a molecular sieve. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant comprises zeolite. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant comprises trisorb. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant present in the shell is spaced apart from the electrode and the polymer layer. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present on the surface inside the hermetic envelope. The electronic device and / or method according to claim 1 or 2, wherein the polymer electronic device further comprises a substrate supporting the polymer layer and the electrode, and a desiccant is present on the surface of the substrate. 3. An electronic device and / or method according to claim 1 and / or 2, wherein a desiccant is attached to a surface inside the hermetic envelope. 3. An electronic device and / or method according to claim 1 and / or 2, wherein a desiccant is adhered to a surface inside the hermetic envelope. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present as a compressed pallet. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present as a powder embedded in the porous packet. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present as a solid embedded in the porous gel. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present as a solid embedded in the membrane. The electronic device and / or method according to claim 1 and / or 2, wherein the desiccant is present as a solid embedded in the adhesive. The electronic device and / or method according to claim 1 and / or 2, wherein the pair of electrodes comprises a positive electrode and a negative electrode, and the negative electrode comprises a metal or metal oxide which is a low work function of moisture reactivity. The electronic device according to claim 1 and / or 2, wherein the pair of electrodes comprises an anode and a cathode, the cathode comprising an alkaline earth metal or metal oxide, which is a low work function of moisture reactivity. Or the way. 3. The method of claim 1 and / or 2, wherein the pair of electrodes comprises an anode and a cathode, the cathode comprising a moisture reactive material selected from calcium, barium, strontium, calcium oxide, barium oxide and strontium oxide. An electronic device and / or method characterized by the above. The electronic device and / or method according to claim 1 and / or 2, wherein the polymer electronic device is a light emitting diode. The electronic device and / or method according to claim 1 and / or 2, wherein the polymer electronic device is a photoreaction detector. The electronic device and / or method according to claim 1 and / or 2, wherein the hermetic envelope is formed of multiple pieces bonded together with an adhesive. The electronic device and / or method according to claim 1 and / or 2, wherein the adhesive is a low temperature adhesive. The electronic device and / or method according to claim 1 or 2, wherein the low temperature adhesive is epoxy. The electronic device and / or method according to claim 1 and / or 2, wherein the hermetic sheath comprises a base adhered to the lid. 3. The method of claim 1 and / or 2, wherein the polymer electronic device further comprises a substrate supporting the polymer layer and the electrode, wherein the hermetic envelope comprises a base adhered to the lid with the substrate serving as the base. An electronic device and / or method characterized by the above.