CN108982599A - Porous silicon-base tungsten oxide film composite material gas sensor and its preparation method and application - Google Patents
Porous silicon-base tungsten oxide film composite material gas sensor and its preparation method and application Download PDFInfo
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Abstract
The invention discloses a kind of porous silicon-base tungsten oxide film composite material gas sensors and its preparation method and application, it is made of porous silicon-base bottom, Pt membrane electrode, porous silicon-base tungsten oxide sensitive layer and rectangular Pt electrode thereon, tungsten oxide (WO of the porous silicon-base tungsten oxide sensitive layer by porous silicon layer and constant potential electrochemical deposition on it3) film composition.Then the present invention utilizes electrochemical process growth in situ WO on porous silicon by preparing Ohm contact electrode at porous silicon-base bottom3The method of particle film is relatively simple, and the process conditions of required control are less, low in cost；The porous silicon-base tungsten oxide film composite material gas sensor prepared can detect low concentration nitrogen dioxide gas at room temperature, have the characteristics that sensitivity is higher, response/restorability is preferable, selective and reproducible.
Description
Technical field
The invention belongs to gas sensor fields, detect the more of nitrogen dioxide gas at room temperature more particularly to a kind of use
Hole silicon substrate tungsten oxide film composite material gas sensor and its preparation method and application.
Background technique
The modern industry of high speed development also brings problem of environmental pollution, atmosphere pollution conduct while bringing huge convenient
A main problem in environmental pollution causes the extensive concern of various circles of society, the annual amount of pollutants ten for entering atmosphere
It is point surprising, it is many kinds of, it has been found that have obvious harm or substantially had more than 100 kinds by what people paid attention to, wherein to environment
What quality was affected have nitrogenous compound, sulfur-containing compound, suspended particulate substance (SPM), the oxide of carbon, hydrocarbon,
Photochemical oxidant etc..
Nitrogen dioxide (NO in atmosphere2) gas is mainly derived from the pollution sources such as vehicle exhaust and industrial waste gas, it will cause
Big gas and water and soil pollution are one of the main reason for causing acid rain, moreover it is possible to make water acidification, eutrophication, it is serious to pollute
Environment, while NO2It can cause the respiratory disorders such as pulmonary edema, great threat is constituted to the health of the mankind.Developing can be right
NO2The high-performance gas sensor of new generation that equal toxic and harmful gas are quickly and effectively detected has highlighted its important meaning
Justice.However, the gas sensor of existing market is mostly the low-dimensional metal oxide using aluminium oxide ceramics etc. as substrate
(ZnO、SnO2、WO3Deng) micro Nano material gas sensor, in the prevalence of operating temperature higher (about 200-400 DEG C), power consumption
Microminaturization that is larger, being unfavorable for sensor, cannot be compatible with si-substrate integrated circuit system process the disadvantages of.Therefore, gas is reduced
The operating temperature (or even realizing working and room temperature) of dependent sensor, developing low-power consumption gas sensor easy of integration becomes the field
Important research direction, nowadays, realize to low concentration of NO2Room temperature detection be still the project for being rich in challenge.
Currently, silicon substrate porous silicon (PS) is considered as most promising one of room temperature gas sensitive.Firstly, by micro-
Nano-silicon cluster be skeleton porous silicon due to its huge specific surface area at room temperature to NO2、NH3Etc. multiple gases have
Air-sensitive performance, this operating temperature and power consumption for reducing device, stability and the reliability for improving device be extremely important；Its
Secondary, silicon substrate porous silicon can be used as substrate, and to support other micro-nano gas sensitives buildings mutually simultaneous with si-substrate integrated circuit system
The micro-nano gas sensor of appearance；The preparation process of third, porous silicon is simple, low in cost, can be in the electrolyte of hydrofluoric acid containing
In prepared with electrochemical erosion method.However, due to being difficult to meet high porosity and duct order coexists leads to porous silicon
The air-sensitive selection performance and stabilization of high Gas-sensing measurment and excellent gas response/restorability and porous silicon can not be had both
Performance is poor etc., and these problems limit the practical application of porous silicon gas sensor.
Summary of the invention
For the deficiencies in the prior art, the present invention provides a kind of porous silicon-base tungsten oxide (WO3) film composite material
Expect gas sensor and its preparation method and application, exists using Preparing Porous Silicon by Double-cell Electrochemistry Etching, and with electrochemical process
Its surface controllable growth WO3Film constructs porous silicon-base tungsten oxide (WO3) film composite material gas sensor, it can be realized
At room temperature to NO2The high sensitivity of gas, quick response/recovery characteristics, highly selective and stiff stability detection.
The present invention is achieved by the following technical solutions:
A kind of porous silicon-base tungsten oxide film composite material gas sensor, including it is porous silicon-base bottom, Pt membrane electrode, porous
Silicon substrate tungsten oxide sensitive layer and Pt electrode；The porous silicon-base bottom is prepared using double-cell electrochemical etching, average hole
Diameter is 1-2 μm, and with a thickness of 5-15 μm, the porous silicon-base tungsten oxide sensitive layer is arranged on the porous silicon-base bottom, should
Porous silicon-base tungsten oxide sensitive layer carries out constant potential electrochemical deposition tungsten oxide film using three-electrode system and is made, described
Porous silicon upper surface of substrate boundary is provided with Pt membrane electrode, which is made using magnetron sputtering plating method, with a thickness of
90-110nm, area are (8-10) mm × (1.5-2.5) mm, and the porous silicon-base tungsten oxide sensitive layer and Pt membrane electrode are mutual
It does not contact, two pieces of rectangular Pt electrodes, the Pt electrode is symmetrically arranged on the porous silicon-base tungsten oxide sensitive layer
Use mask with magnetron sputtering method, there are tungsten oxide particles in the duct of the porous silicon-base tungsten oxide sensitive layer.
A kind of porous silicon-base tungsten oxide film composite material gas sensor and preparation method thereof, comprising the following steps:
(1) cleaning of silicon wafer
Silicon wafer is put into hydrogen peroxide (H2O2, 30wt.%) and the concentrated sulfuric acid (H2SO4, 98wt.%) mixed liquor in impregnate 29-
31min removes the hard particles of silicon chip surface, hydrogen peroxide (H in above-mentioned mixed liquor2O2, 30wt.%) and the concentrated sulfuric acid (H2SO4,
Volume ratio 98wt.%) is 1:3；
It is rinsed well with deionized water in the mixed liquor for being placed on hydrofluoric acid (HF, 40wt.%) and deionized water and impregnates 19-
21min removes the SiO on surface2Layer, the volume ratio of hydrofluoric acid (HF, 40wt.%) and deionized water is 1 in above-mentioned mixed liquor:
1；
Silicon wafer is sequentially placed into deionized water, acetone solvent and dehydrated alcohol and is cleaned by ultrasonic 9-11min respectively, removes table
It is put into after the organic impurities of face spare in dehydrated alcohol.
Silicon wafer is that p-type list throws silicon wafer in above-mentioned steps (1), and crystal orientation is<100>, and resistivity is 9-10 Ω cm, with a thickness of
490-510 μm, cut lengths are (23-25) mm × (8-10) mm.
(2) porous silicon is prepared
Will cleaning is completed in above-mentioned steps (1) silicon wafer as porous silicon-base bottom, using double-cell electrochemical etching in N,
Pass through constant current etching silicon wafer in the corrosive liquid of dinethylformamide (DMF99.5wt.%) and hydrofluoric acid (HF, 40wt.%)
Polished surface prepare porous silicon layer, above-mentioned n,N-Dimethylformamide (DMF, 99.5wt.%) and hydrofluoric acid (HF,
Volume ratio 40wt.%) is 2.5:1, and corrosive liquid temperature is controlled in room temperature and not by illumination, and the corrosion current of application is close
Degree is 98-102mA/cm2, etching time 9-11min.
The average pore size of above-mentioned porous silicon layer is 1-2 μm, and with a thickness of 5-15 μm, porous silicon layer area size is (15-
17) mm×(3-5)mm。
(3) tungsten oxide (WO is grown on porous silicon layer3) film
Using platinum as target, a layer thickness is deposited in porous silicon layer upper surface boundary using magnetron sputtering embrane method
For 90-110nm, area is (8-10) mm × (1.5-2.5) mm Pt membrane electrode, is ensured using copper wire and Pt membrane electrode spot welding
Pt membrane electrode and porous silicon form Ohmic contact, and then extraction copper wire is sealed with silica gel；Tungsten powder is dissolved in diluted dioxygen
Water (H2O2, 30wt.%) in stirring, excessive H is catalytically decomposed with Pt net2O2Afterwards, isopropanol/H that volume ratio is 1:1 is added2O
Mixed liquor, be configured to tungsten concentration be 50 × 10-3The electrolyte of M.Constant potential electrochemical deposition oxygen is carried out using three-electrode system
Change tungsten (WO3) film, after having deposited, place the product in 1.5-2.5h is heat-treated at 440-450 DEG C of Muffle furnace, obtain porous silicon
Base tungsten oxide film composite material.
Porous silicon-base tungsten oxide (the WO prepared in above-mentioned steps (3)3) in film composite structure porous silicon surface by one layer
Netted tungsten oxide (WO3) membrana granulosa covering, and have a little tungsten oxide (WO3) micro-/ nano distribution of particles is thereon.
The quality purity of target metal platinum is 99.95% in above-mentioned steps (3), and background vacuum is (4-5) × 10-4Pa,
Working gas is the argon gas that purity is 99.99%, operating pressure 1.5-2.5Pa, and temperature is room temperature, sputtering power 85-95W,
Sputtering time 9-12min；
It is electric as auxiliary for the Pt net of 24mm × 9mm using area using porous silicon as working electrode in above-mentioned step (3)
Pole, it is 1.8-2.2cm that two electrodes, which keep spacing, using saturated calomel electrode (SCE) as reference electrode.
The sedimentation potential range of constant potential electrochemical deposition in above-mentioned step (3): relative to reference electrode -0.4005
The constant potential of~-0.3995V carries out electrochemical deposition, and the magnetic stir bar in deposition process in solution is with the speed of 300r/min
Rate persistently stirs, and control electrodeposition time is 58-62min.
(4) porous silicon-base tungsten oxide film composite material gas sensor is prepared
By porous silicon-base tungsten oxide film composite material made from step (3) with being dried with nitrogen, ultrahigh vacuum is placed in target
The vacuum chamber of magnetron sputtering apparatus uses mask heavy in composite material surface with magnetron sputtering method using platinum as target
Product forms 2 rectangular Pt electrodes with a thickness of 90-110nm, constructs porous silicon-base tungsten oxide film composite material gas sensing
Device.
The quality purity of target metal platinum in above-mentioned steps (4) is 99.95%, and background vacuum is (4-5) × 10- 4Pa, working gas are the argon gas that purity is 99.99%, and operating pressure 1.5-2.5Pa, temperature is room temperature, sputtering power 85-
95W, sputtering time 9-12min.
The invention has the advantages and beneficial effects that:
1) present invention is then former on porous silicon using electrochemical process by preparing Ohm contact electrode at porous silicon-base bottom
Position growth WO3The method of particle film is relatively simple, and the process conditions of required control are less, low in cost；
2) the porous silicon-base tungsten oxide film composite material gas sensor that the present invention prepares can detect low at room temperature
Concentration nitrogen dioxide gas has the characteristics that sensitivity is higher, response/restorability is preferable, selective and reproducible.
Detailed description of the invention
Fig. 1 is that the present invention prepares porous silicon-base tungsten oxide (WO3) film composite material gas sensor preparation flow figure；
Fig. 2 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor structural representation
Figure；
Fig. 3 is scanning electron microscope (SEM) photo on porous silicon layer surface prepared by the present invention；
Fig. 4 is scanning electron microscope (SEM) photo of porous silicon layer section prepared by the present invention；
Fig. 5 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material surface scanning electron microscope
(SEM) photo；
Fig. 6 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material section scanning electron microscope
(SEM) photo；
Fig. 7 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material high power (50K times) scanning electron
Microscope (SEM) photo；
Fig. 8 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material 450 DEG C anneal 2 hours after
X x ray diffraction (XRD) map；
Fig. 9 is the partial enlarged view of Fig. 8；
Figure 10 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material Raman spectrogram；
Figure 11 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material power spectrum (EDS) figure；
Figure 12 is typical resistive memory gas sensor gas-sensitive property curve；
Figure 13 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor is in different temperatures
Under to 1ppm NO2Gas-sensing measurment comparison diagram；
Figure 14 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor connects at room temperature
Continuous 4 times to 1ppm NO2Air-sensitive response-recovery loop test figure；
Figure 15 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor is right at room temperature
Various concentration NO2The dynamic air-sensitive response curve of gas；
Figure 16 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor exists at room temperature
At room temperature to the Gas-sensing measurment comparison diagram of gas with various；
Wherein, 1, porous silicon-base bottom；2, Pt electrode；3, porous silicon-base tungsten oxide sensitive layer；4, Pt membrane electrode.
Specific embodiment
Technical solution of the present invention is further illustrated combined with specific embodiments below.It should be understood that following embodiments
Be it is illustrative, be not restrictive, cannot be limited the scope of protection of the present invention with following embodiments.
The raw materials used present invention is commercially available chemically pure reagents.Silicon wafer is provided using Suzhou Jing Xi Electronic Science and Technology Co., Ltd.
4 inches of single-sided polishing p-type silicon chips of Prime grade, crystal orientation be<100>, resistivity be 9-10 Ω cm, with a thickness of 500 μm.It is super
High vacuum facing-target magnetron sputtering system instrument is the DPS-III type ultrahigh vacuum pair of Shenyang scientific instrument development center Co., Ltd manufacture
Targets magnetic sputtering film plating machine, Muffle furnace model SX2-2.5-10A.
Porous silicon-base tungsten oxide film composite material gas sensor prepared by the present invention is by porous silicon-base bottom 1, Pt film electricity
Pole 4, porous silicon-base tungsten oxide sensitive layer 3 and rectangular Pt electrode 2 thereon form, and the porous silicon-base tungsten oxide is sensitive
Tungsten oxide (WO of the layer 3 by porous silicon layer and constant potential electrochemical deposition on it3) film composition.
The present invention as shown in Figure 1 prepares porous silicon-base tungsten oxide (WO3) film composite material gas sensor preparation
Flow chart can be seen that porous silicon-base tungsten oxide (WO3) film composite material gas sensor the preparation method comprises the following steps:
(1) silicon wafer is cut into the rectangle print having a size of 24mm × 9mm, is put into hydrogen peroxide (H2O2, 30wt.%) with
The concentrated sulfuric acid (H2SO4,98wt.%) mixed liquor in impregnate 30min, the hard particles of silicon chip surface are removed, in above-mentioned mixed liquor
Hydrogen peroxide (H2O2, 30wt.%) and the concentrated sulfuric acid (H2SO4,98wt.%) volume ratio be 1:3；After being rinsed well with deionized water
It is placed in hydrofluoric acid (HF, 40wt.%) and the mixed liquor of deionized water and impregnates 20min, remove the SiO on surface2Layer, it is above-mentioned mixed
Closing the volume ratio of hydrofluoric acid (HF, 40wt.%) and deionized water in liquid is 1:1；Silicon wafer is sequentially placed into deionized water, acetone
It is cleaned by ultrasonic 10min in solvent and dehydrated alcohol respectively, is put into after removal surface organic matter impurity spare in dehydrated alcohol.
(2) using the silicon wafer that cleaning is completed in above-mentioned steps (1) as porous silicon-base bottom 1, using double-cell electrochemical etching
It is carved in the mixed solution of n,N-Dimethylformamide (DMF99.5wt.%) and hydrofluoric acid (HF, 40wt.%) by constant current
The polished surface of silicon wafer is lost to prepare porous silicon layer, above-mentioned n,N-Dimethylformamide (DMF, 99.5wt.%) and hydrofluoric acid
The volume ratio of (HF, 40wt.%) is 2.5:1, and the control of corrosive liquid temperature is not in room temperature and by illumination, the corrosion electricity of application
Current density is about 100mA/cm2, etching time is about 10min, and porous silicon layer area size is 16mm × 4mm.Fig. 3 and Fig. 4 are
The porous silicon layer surface of preparation and scanning electron microscope (SEM) photo of section, by Fig. 3 and Fig. 4 it can be seen that porous silicon
The average pore size of layer is 1.5 μm, with a thickness of 10 μm, porosity 40%.
(3) in order to measure the electrology characteristic of porous silicon layer, platinum (Pt) metal electrode is prepared with true on the surface of porous silicon layer
It protects electrode and porous silicon forms Ohmic contact, using platinum as target, using ultrahigh vacuum facing-target magnetron sputtering system instrument, with pure
For the platinum that degree is 99.95% as target, background vacuum is 4.5 × 10-4Pa, working gas are that purity is 99.99%
Argon gas, operating pressure 2.0Pa, temperature are room temperature, sputtering power 90W, sputtering time 10min, using magnetron sputtering embrane method
It is 100nm that in porous silicon layer upper surface, boundary, which deposits a layer thickness, and area is the Pt membrane electrode 4 of 9mm × 2mm, Pt membrane electrode
After the completion of 4 sputterings, ensures that Pt membrane electrode 4 and porous silicon form Ohmic contact using copper wire and 4 spot welding of Pt membrane electrode, then use
Extraction copper wire is sealed in silica gel；1.84g tungsten powder is dissolved in the diluted hydrogen peroxide (H of 50ml2O2, 30wt.%) in stirring, use
Excessive H is catalytically decomposed in Pt net2O2Afterwards, isopropanol/H that volume ratio is 1:1 is added2The mixed liquor of O, being configured to tungsten concentration is 50
×10-3The electrolyte of M.Constant potential electrochemical deposition tungsten oxide (WO is carried out using three-electrode system3) film, it is with porous silicon
Working electrode, using Pt net as auxiliary electrode, it is 2cm that two electrodes, which keep spacing, using saturated calomel electrode (SCE) as reference
Electrode uses electrochemical analyser to carry out electrochemical deposition relative to the constant potential of reference electrode -0.4V, molten in deposition process
Magnetic stir bar in liquid is persistently stirred with the rate of 300r/min, and control electrodeposition time is 60min, after having deposited, will be produced
Object is placed in Muffle furnace and is heat-treated 2h at 450 DEG C, obtains porous silicon-base tungsten oxide film sensitive layer 3.
Utilize electrochemical process growth in situ tungsten oxide (WO on porous silicon3) particle film method it is relatively simple, it is required
The process conditions of control are less, low in cost.
Fig. 5 to Fig. 7 is porous silicon-base tungsten oxide (WO prepared by the present invention3) 3 surface of film sensitive layer, section and amplification
Scanning electron microscope (SEM) photo under 50K times, porous silicon layer surface is netted by one layer it can be seen from Fig. 5 to Fig. 7
Tungsten oxide (WO3) film covering, there are also the tungsten oxide (WO that some partial sizes are about several hundred nanometers in duct3) nanocrystal, this increasing
Big porous silicon-base tungsten oxide (WO3) film sensitive layer 3 specific surface, provide more adsorption potentials for gas molecule, ensure
Porous silicon-base tungsten oxide (WO3) film sensitive layer 3 have preferable Gas-sensing measurment and faster response recovery time.
Fig. 8 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film sensitive layer 3 450 DEG C anneal 2 hours after
X x ray diffraction (XRD) map nearby has a very strong diffraction maximum in 2 θ=33 °, is (200) diffraction at porous silicon-base bottom
Peak, Fig. 9 are the partial enlarged view (22.0-25.0 °) of dotted line middle section in Fig. 8 XRD spectrum, wherein there is 3 apparent to spread out
It penetrates peak and respectively corresponds tungsten oxide (WO3) monocline crystal phase (002), (020) and (002) diffraction maximum, the position of these diffraction maximums and
Tungsten oxide (WO3) monocline crystal phase diffraction maximum it is consistent (JCPDS NO.43-1035), it was demonstrated that this compound is porous silicon-base oxygen
Change tungsten (WO3) film composite material.
Figure 10 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film sensitive layer 3 Raman spectrogram, in figure
520cm-1Neighbouring peak is the Raman scattering peak at porous silicon-base bottom, 715cm-1And 804cm-12 neighbouring peaks belong to O-W6+- O's
Beam mode shows that porous silicon layer surface main component is tungsten oxide (WO3).Positioned at 272cm-1Peak belong to W-O-W bridge
The beam mode of oxygen is connect, and frequency is located at 135cm-1Raman peaks are due to tungsten oxide (WO3) caused by lattice mode, further test
Having demonstrate,proved this compound is porous silicon-base tungsten oxide (WO3) film composite material.
Figure 11 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film sensitive layer 3 power spectrum (EDS) figure, from figure
It can be seen that porous silicon-base tungsten oxide (WO3) film sensitive layer 3 essential element be Si, W, O and C (be probably derived from conduction
Glue) it also assists demonstrating tungsten oxide (WO3) be deposited on porous silicon layer surface.
(4) porous silicon-base tungsten oxide film sensitive layer 3 made from step (3) is placed in ultrahigh vacuum pair with being dried with nitrogen
The vacuum chamber of target magnetic control sputtering equipment is used as target using the platinum that quality purity is 99.95%, background vacuum for 4.5 ×
10-4Pa, working gas are the argon gas that purity is 99.99%, operating pressure 2.0Pa, and temperature is room temperature, sputtering power 90W,
Sputtering time 10min uses mask to deposit to form 2 sides with a thickness of 100nm in composite material surface with magnetron sputtering method
The Pt electrode 2 of shape constructs porous silicon-base tungsten oxide film composite material gas sensor.
In order to more accurately describe the performance of resistive memory gas sensor, following key property is generally used
Parameter evaluates gas sensor.
(1) sensitivity sensitivity (S)
Sensitivity is for characterizing gas sensor to the physical quantity of tested gas sensitization degree.For common resistance-type half
Conductor gas sensor, can be used resistance ratio representation, i.e. the resistance value Rg with sensor under test gas and its in air
In resistance value Ra ratio indicate:
(2) response/recovery time
Response/recovery time is for reflecting gas sensor response speed of its resistance to tested gas at the working temperature
Restore speed with resistance after the tested gas of disengaging.Figure 12 is that typical resistive memory gas sensor gas-sensitive property is bent
Line, the response time is expressed as element and contacts time of the changing value of sensitivity S when responding after tested gas from 0 to 90% in figure,
Recovery time is expressed as element and is detached from time of the changing value of sensitivity S when restoring after tested gas from 0 to 90%.
(3) selectivity
Since the type of gas is more, their nature difference is also very big, therefore any kind of gas sensor is not
The gas of all kinds can be detected simultaneously.Generally, a kind of gas sensor can only be used to detect certain a kind of gas.Selectivity
It is used to indicate that gas sensor is tested the recognition capability of gas to certain (class) and to the anti-interference energy of other kinds of (class) gas
Power.The quality of selectivity reflects the power of gas sensor anti-interference ability.
(4) operating temperature
It is optimal by the certain heat competence exertion of extraneous offer since gas sensor generally requires at a certain temperature
Air-sensitive performance.At different temperature, the gas-sensitive property (sensitivity, response/recovery time and selectivity etc.) of gas sensor is past
Toward difference.Operating temperature is exactly temperature when gas sensor can play best air-sensitive performance.
(5) stability
Stability is intended to indicate that gas sensor to the anti-interference ability of other factors other than detection gas, such as to the time
Extension and ambient enviroment (temperature, humidity etc.) variation anti-interference ability, generally can using sensitivity at any time
The stability changed to reflect gas sensor of (or with temperature, humidity etc.).
The present invention measures porous silicon-base tungsten oxide (WO using static volumetric method at room temperature3) film composite material air-sensitive biography
Sensor defines (such as NO in an oxidizing atmosphere to the sensitivity characteristic of detection gas2Equal gases) gas sensor sensitivity S
=Ra/Rg, and (such as NH under reducing atmosphere3Equal gases) gas sensor sensitivity S=Rg/Ra, wherein Rg、RaRespectively
For resistance value of the gas sensor in detection gas and dry air.
Figure 13 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor is in different temperatures
Under to 1ppm NO2Gas-sensing measurment comparison diagram；By can be seen that the present invention has highest air-sensitive under room temperature (25 DEG C)
Sensitivity, therefore porous silicon-base tungsten oxide (WO of the invention3) optimum operating temperature of film composite material gas sensor is
Room temperature (25 DEG C).
Figure 14 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor connects at room temperature
Continuous 4 times to 1ppm NO2Air-sensitive response-recovery loop test figure；Porous silicon-base tungsten oxide (WO in air-sensitive response each time3)
Film composite material gas sensor all has essentially identical Gas-sensing measurment and response/recovery time, this illustrates the air-sensitive
Sensor has preferable repeatability and stability.
Figure 15 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor is right at room temperature
Various concentration NO2The dynamic air-sensitive response curve of gas；To 0.2ppm, 0.5ppm, 1.0ppm, 2.0ppm NO2The spirit of gas
Sensitivity is respectively 1.67,2.38,2.62 and 2.75, and the gas sensor has good invertibity and quick gas
Body response/recovery characteristics, at room temperature to 1ppmNO2The response time of gas is about 80s, and recovery time is about 105s.
Figure 16 is porous silicon-base tungsten oxide (WO prepared by the present invention3) film composite material gas sensor exists at room temperature
At room temperature to the Gas-sensing measurment comparison diagram of gas with various；In order to assess porous silicon-base tungsten oxide (WO3) film composite material gas
Dependent sensor is to NO2Air-sensitive selectivity, be also tested for the gas sensor at room temperature to NH3、H2S, formaldehyde, ethyl alcohol, third
The air-sensitive of the other five kinds of gases of ketone responds.Porous silicon-base tungsten oxide (WO as seen from Figure 163) film composite material air-sensitive biography
Sensor is at room temperature to 1ppm NO2Gas-sensing measurment be 2.62, the sensitivity of significantly larger than other several gases, this shows
The gas sensor is in room temperature to low concentration of NO2Gas has preferable selectivity.
In conclusion the porous silicon-base tungsten oxide (WO that the present invention prepares3) film composite material gas sensor can be
Detect low concentration nitrogen dioxide gas at room temperature, have sensitivity is higher, response/restorability preferably, selectivity and repeatability
Good feature.
Illustrative description has been done to the present invention above, it should explanation, the case where not departing from core of the invention
Under, any simple deformation, modification or other skilled in the art can not spend the equivalent replacement of creative work equal
Fall into protection scope of the present invention.
Claims (10)
1. a kind of porous silicon-base tungsten oxide film composite material gas sensor, which is characterized in that including porous silicon-base bottom, Pt film
Electrode, porous silicon-base tungsten oxide sensitive layer and Pt electrode；The porous silicon-base bottom using double-cell electrochemical etching prepare and
At average pore size is 1-2 μm, and with a thickness of 5-15 μm, the porous silicon-base tungsten oxide is arranged on the porous silicon-base bottom
Sensitive layer, the porous silicon-base tungsten oxide sensitive layer carry out constant potential electrochemical deposition tungsten oxide film system using three-electrode system
, the porous silicon upper surface of substrate boundary is provided with Pt membrane electrode, which uses magnetron sputtering plating legal system
, with a thickness of 90-110nm, area is (8-10) mm × (1.5-2.5) mm, the porous silicon-base tungsten oxide sensitive layer and Pt
Membrane electrode is not in contact with each other, and two pieces of rectangular Pt electrodes are symmetrically arranged on the porous silicon-base tungsten oxide sensitive layer, described
Pt electrode use mask with magnetron sputtering method, there are tungsten oxides in the duct of the porous silicon-base tungsten oxide sensitive layer
Grain.
2. gas sensor according to claim 1, which is characterized in that the porous silicon-base bottom is with single-sided polishing p-type
Silicon wafer is raw material, prepares porous silicon layer by the polished surface of constant current etching silicon wafer using double-cell electrochemical etching；By
The volume ratio of n,N-Dimethylformamide and hydrofluoric acid composition corrosive liquid, n,N-Dimethylformamide and hydrofluoric acid is (2-2.5):
1, hydrofluoric acid is the hydrofluoric acid aqueous solution of mass percent 40-50wt.%, and corrosive liquid temperature is controlled at 20-25 degrees Celsius of room temperature
And not by illumination, the corrosion electric current density of application is 98-102mA/cm2, etching time 9-11min.
3. gas sensor according to claim 1, which is characterized in that the porous silicon-base tungsten oxide sensitive layer uses
Three-electrode system carries out constant potential electrochemical deposition method deposited oxide W film on porous silicon-base bottom and prepares, by being dissolved in dilution
Hydrogen peroxide in tungsten powder isopropanol and H is added2The mixed liquor of O forms electrolyte, and tungsten concentration is (45-55) × 10-3M, dioxygen
The mass percent of water is 25-35wt.%, isopropanol and H2The volume ratio of the mixed liquor of O is 1:1, at 440-450 DEG C at heat
1.5-2.5h is managed, magnetic stir bar rate is 300r/min in deposition process, and control electrodeposition time is 55-65min.
4. gas sensor according to claim 1, which is characterized in that the Pt membrane electrode is using platinum as target
Material is deposited on porous silicon upper surface of substrate boundary using magnetron sputtering embrane method, and background vacuum is (4-5) × 10-4Pa, work
Making gas is argon gas, and operating pressure 1.5-2.5Pa, temperature is 20-25 degrees Celsius of room temperature, sputtering power 85-95W, when sputtering
Between 9-12min.
5. gas sensor according to claim 1, which is characterized in that the Pt electrode using platinum as target,
Mask is used to deposit with magnetron sputtering method in the porous silicon-base tungsten oxide sensitivity layer surface, background vacuum is
(4-5)×10-4Pa, working gas are argon gas, and operating pressure 1.5-2.5Pa, temperature is 20-25 degrees Celsius of room temperature, sputters function
Rate 85-95W, sputtering time 5-15min.
6. gas sensor according to claim 1, which is characterized in that described is present in porous silicon-base tungsten oxide sensitivity
Hundred nanometer scale of tungsten oxide particles in the duct of layer is less than 500nm.
7. special such as according to the preparation method of porous silicon-base tungsten oxide film composite material gas sensor described in claim 1
Sign is, comprising the following steps:
(1) cleaning of silicon wafer
Silicon wafer is put into the mixed liquor of 30wt.% hydrogen peroxide and the 98wt.% concentrated sulfuric acid and impregnates 29-31min, removes silicon chip surface
Hard particles, the volume ratio of 30wt.% hydrogen peroxide and the 98wt.% concentrated sulfuric acid is 1:3 in above-mentioned mixed liquor；
It is rinsed well with deionized water in the mixed liquor for being placed on 40wt.% hydrofluoric acid and deionized water and impregnates 19-21min, gone
Except the SiO on surface2Layer, the volume ratio of 40wt.% hydrofluoric acid and deionized water is 1:1 in above-mentioned mixed liquor；
Silicon wafer is sequentially placed into deionized water, acetone solvent and dehydrated alcohol and is cleaned by ultrasonic 9-11min respectively, removal surface has
It is put into after machine object impurity spare in dehydrated alcohol；
(2) porous silicon is prepared
Using the silicon wafer that cleaning is completed in above-mentioned steps (1) as porous silicon-base bottom, existed using double-cell electrochemical etching
Pass through the polishing table of constant current etching silicon wafer in the corrosive liquid of 99.5wt.%N, dinethylformamide and 40wt.% hydrofluoric acid
Face prepares porous silicon layer, above-mentioned 99.5wt.%N, and the volume ratio of dinethylformamide and 40wt.% hydrofluoric acid is 2.5:1,
For the control of corrosive liquid temperature in room temperature and not by illumination, the corrosion electric current density of application is 98-102mA/cm2, etching time
For 9-11min；
(3) tungsten oxide film is grown on porous silicon layer
Using platinum as target, use magnetron sputtering embrane method porous silicon layer upper surface boundary deposit a layer thickness for
90-110nm, area are (8-10) mm × (1.5-2.5) mm Pt membrane electrode, ensure Pt film using copper wire and Pt membrane electrode spot welding
Electrode and porous silicon form Ohmic contact, and then extraction copper wire is sealed with silica gel；Tungsten powder is dissolved in the hydrogen peroxide of 30wt.%
Excessive H is catalytically decomposed with Pt net in middle stirring2O2Afterwards, isopropanol/H that volume ratio is 1:1 is added2The mixed liquor of O, is configured to tungsten
Concentration is 50 × 10-3The electrolyte of M；Constant potential electrochemical deposition tungsten oxide film is carried out using three-electrode system, after having deposited,
Place the product in 1.5-2.5h is heat-treated at 440-450 DEG C in Muffle furnace, porous silicon-base tungsten oxide film composite material is obtained；
(4) porous silicon-base tungsten oxide film composite material gas sensor is prepared
By porous silicon-base tungsten oxide film composite material made from step (3) with being dried with nitrogen, ultrahigh vacuum is placed in target magnetic control
The vacuum chamber of sputtering equipment uses mask to deposit shape in composite material surface with magnetron sputtering method using platinum as target
At 2 rectangular Pt electrodes with a thickness of 90-110nm, porous silicon-base tungsten oxide film composite material gas sensor is constructed.
8. the preparation method of gas sensor according to claim 4, which is characterized in that background is true in the step (3)
Reciprocal of duty cycle is (4-5) × 10-4Pa, working gas are argon gas, and operating pressure 1.5-2.5Pa, temperature is 20-25 degrees Celsius of room temperature,
Sputtering power 85-95W, sputtering time 9-12min；
Using porous silicon as working electrode in the step (3), using area for 24mm × 9mm Pt net as auxiliary electrode, two
It is 1.8-2.2cm that electrode, which keeps spacing, using saturated calomel electrode as reference electrode；
The sedimentation potential range of constant potential electrochemical deposition in above-mentioned step (3): relative to reference electrode -0.4005~-
The constant potential of 0.3995V carries out electrochemical deposition, and the magnetic stir bar in deposition process in solution is held with the rate of 300r/min
Continuous stirring, control electrodeposition time are 58-62min.
9. the preparation method of gas sensor according to claim 4, which is characterized in that background is true in the step (4)
Reciprocal of duty cycle is (4-5) × 10-4Pa, working gas are argon gas, and operating pressure 1.5-2.5Pa, temperature is 20-25 degrees Celsius of room temperature,
Sputtering power 85-95W, sputtering time 9-12min.
10. such as according to porous silicon-base tungsten oxide film composite material gas sensor described in claim 1, or want according to right
Application of the porous silicon-base tungsten oxide film composite material gas sensor for asking 4 preparation methods to obtain in detection nitrogen dioxide,
At room temperature to 1ppmNO2The response time of gas is 80s, recovery time 105s, at room temperature to 1ppm NO2Air-sensitive it is sensitive
Degree is 2.62.
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109594044A (en) * | 2018-12-13 | 2019-04-09 | 天津大学 | Tungsten oxide nanoparticles and porous silicon composite structure gas sensor and preparation method |
| CN109991286A (en) * | 2019-05-05 | 2019-07-09 | 河北工业大学 | A kind of preparation method of the double selectivity gas sensor of aluminium doped tungsten oxide base |
| CN110240118A (en) * | 2019-05-22 | 2019-09-17 | 江苏大学 | A kind of higher middle resistance p-type porous silicon film of porosity and its fast preparation method |
| CN110294454A (en) * | 2019-05-22 | 2019-10-01 | 江苏大学 | The macro hole silicon structure of resistance p-type and its fast preparation method in a kind of high-aspect-ratio |
| CN111245081A (en) * | 2020-01-21 | 2020-06-05 | 电子科技大学 | Self-powered automobile exhaust sensor and method |
| CN111487288A (en) * | 2019-01-27 | 2020-08-04 | 天津师范大学 | Porous silicon-based multi-walled carbon nanotube composite gas sensor and preparation method and application thereof |
| CN113758974A (en) * | 2021-08-30 | 2021-12-07 | 中国科学院合肥物质科学研究院 | Oxide semiconductor gas sensor and preparation method and application thereof |
| CN114235903A (en) * | 2020-09-09 | 2022-03-25 | 中国科学院苏州纳米技术与纳米仿生研究所 | Gas sensor and manufacturing method thereof |
| CN114778615A (en) * | 2022-04-29 | 2022-07-22 | 遵义师范学院 | Composite nano material array gas sensor and preparation method thereof |
| WO2024183108A1 (en) * | 2023-03-06 | 2024-09-12 | 江苏大学 | Humidity-interference-resistant hydrogen gas-sensitive material, semiconductor resistance-type hydrogen sensor, intelligent hydrogen sensing system, preparation, and use |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101799443A (en) * | 2010-03-16 | 2010-08-11 | 天津大学 | Method for preparing multiaperture silicon substrate tungsten oxide nanometer thin film gas sensitive transducer |
| CN103063707A (en) * | 2012-12-26 | 2013-04-24 | 天津大学 | Preparation method for gas-sensitive material with composite structure |
| CN103063706A (en) * | 2012-12-26 | 2013-04-24 | 天津大学 | Preparation method for porous silicon based tungsten oxide nanocomposite structure gas sensor |
| CN103424435A (en) * | 2013-08-20 | 2013-12-04 | 天津大学 | Preparation method of porous silicon-based tungsten trioxide nanorod composite-structure gas sensor element |
-
2017
- 2017-06-05 CN CN201710414303.1A patent/CN108982599A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101799443A (en) * | 2010-03-16 | 2010-08-11 | 天津大学 | Method for preparing multiaperture silicon substrate tungsten oxide nanometer thin film gas sensitive transducer |
| CN103063707A (en) * | 2012-12-26 | 2013-04-24 | 天津大学 | Preparation method for gas-sensitive material with composite structure |
| CN103063706A (en) * | 2012-12-26 | 2013-04-24 | 天津大学 | Preparation method for porous silicon based tungsten oxide nanocomposite structure gas sensor |
| CN103424435A (en) * | 2013-08-20 | 2013-12-04 | 天津大学 | Preparation method of porous silicon-based tungsten trioxide nanorod composite-structure gas sensor element |
Non-Patent Citations (2)
| Title |
|---|
| S. BAECK ET AL.: "Controlled Electrodeposition of Nanoparticulate Tungsten Oxide", 《NANO LETTERS》 * |
| 严达利: "多孔硅基金属氧化物纳米复合材料的制备与气敏性能研究", 《中国博士学位论文全文数据库 工程科技I辑》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109594044A (en) * | 2018-12-13 | 2019-04-09 | 天津大学 | Tungsten oxide nanoparticles and porous silicon composite structure gas sensor and preparation method |
| CN111487288A (en) * | 2019-01-27 | 2020-08-04 | 天津师范大学 | Porous silicon-based multi-walled carbon nanotube composite gas sensor and preparation method and application thereof |
| CN109991286A (en) * | 2019-05-05 | 2019-07-09 | 河北工业大学 | A kind of preparation method of the double selectivity gas sensor of aluminium doped tungsten oxide base |
| CN110240118A (en) * | 2019-05-22 | 2019-09-17 | 江苏大学 | A kind of higher middle resistance p-type porous silicon film of porosity and its fast preparation method |
| CN110294454A (en) * | 2019-05-22 | 2019-10-01 | 江苏大学 | The macro hole silicon structure of resistance p-type and its fast preparation method in a kind of high-aspect-ratio |
| CN111245081A (en) * | 2020-01-21 | 2020-06-05 | 电子科技大学 | Self-powered automobile exhaust sensor and method |
| CN114235903A (en) * | 2020-09-09 | 2022-03-25 | 中国科学院苏州纳米技术与纳米仿生研究所 | Gas sensor and manufacturing method thereof |
| CN113758974A (en) * | 2021-08-30 | 2021-12-07 | 中国科学院合肥物质科学研究院 | Oxide semiconductor gas sensor and preparation method and application thereof |
| CN114778615A (en) * | 2022-04-29 | 2022-07-22 | 遵义师范学院 | Composite nano material array gas sensor and preparation method thereof |
| WO2024183108A1 (en) * | 2023-03-06 | 2024-09-12 | 江苏大学 | Humidity-interference-resistant hydrogen gas-sensitive material, semiconductor resistance-type hydrogen sensor, intelligent hydrogen sensing system, preparation, and use |
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