A kind of transistor-type formaldehyde sensor and preparation method thereofTechnical field
The present invention relates to sensor component fields more particularly to a kind of transistor-type formaldehyde sensor and preparation method thereof.
Background technique
Formaldehyde sensor is air-sensitive original part important in domestic environment detection as a kind of semiconductor gas sensor, butBe it is existing have formaldehyde sensor selectivity not high, although its production letter that there is most of semiconductor gas sensor to haveIt is single, at low cost, easy to use, be easy to test macro it is mating, be conveniently replaceable, gas concentration directly can be converted into electric signalThe advantages that, but in practical application there is also stability and poor selectivity, sensitive mechanism is complicated, operating temperature is high, the service life is short etc.How disadvantage improves the comprehensive performance of this kind of sensor into the focus for studying this kind of sensors.
Therefore, the existing technology needs to be improved and developed.
Summary of the invention
In view of above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a kind of transistor-type formaldehyde sensor and itsProduction method, it is intended to solve the problems, such as that formaldehyde sensor stability, selectivity are poor in the prior art.
Technical scheme is as follows:
A kind of transistor-type formaldehyde sensor, wherein including substrate, setting gate electrode on the substrate, be arranged describedDielectric layer on gate electrode, setting laminated film on the dielectric layer, the source electrode being arranged on the laminated film andDrain electrode, the laminated film are the zinc-oxide film for being adsorbed with metal nanoparticle.
The transistor-type formaldehyde sensor, wherein in the laminated film, metal nanoparticle passes through Electrostatic AbsorptionOn zinc-oxide film.
The transistor-type formaldehyde sensor, wherein the metal nanoparticle is gold nano grain, silver nano-grainWith one of Pt nanoparticle or a variety of.
The transistor-type formaldehyde sensor, wherein institute's zinc-oxide film is by the oxygen through alkali metal element doping vario-propertyChange zinc to be made.
The transistor-type formaldehyde sensor, wherein in the zinc-oxide film, alkali metal element and zinc oxide rubYou are than being 0.01:1 ~ 0.15:1.
The transistor-type formaldehyde sensor, wherein the substrate is flexible substrates, and the gate electrode is metal gate electricityPole and the dielectric layer are aluminum oxide dielectric layer.
A kind of production method of transistor-type formaldehyde sensor, wherein comprising steps of
Substrate is provided, and forms gate electrode on the substrate；
Deposition prepares dielectric layer on the gate electrode；
Burnett's solution is provided, on the dielectric layer by burnett's solution coating, annealing forms zinc-oxide film；
Metal nanoparticle is provided, and electrification modification is carried out to zinc-oxide film, then makees metal nanoparticle by electrostaticWith being adsorbed on zinc-oxide film, laminated film is obtained；
Deposition forms source electrode and drain electrode on laminated film, obtains transistor-type formaldehyde sensor.
The production method of the transistor-type formaldehyde sensor, wherein coated by the zinc oxide precursor solutionBefore step on gate electrode, further includes:
Alkali metal hydroxide is added in burnett's solution.
The production method of the transistor-type formaldehyde sensor, wherein by atomic layer deposition method in the gate electrodeUpper deposition of aluminium oxide prepares dielectric layer.
The production method of the transistor-type formaldehyde sensor, wherein the step charges zinc-oxide filmModification, comprising:
Using 3- aminopropyl triethoxysilane solution to zinc-oxide film carry out immersion treatment, then by toluene rinse immersion atZinc-oxide film after reason, it is then dry in nitrogen atmosphere.
The utility model has the advantages that transistor-type formaldehyde sensor provided by the invention, by the way that laminated film is arranged on the dielectric layer, soSource electrode and drain electrode are set on the laminated film again afterwards, are adsorbed with the zinc-oxide film of metal nanoparticle, THIN COMPOSITEFilm can change carrier concentration, surface state and the device transport capacity of transistor, and due to the modification of metal nanoparticle, makeObtaining laminated film PARA FORMALDEHYDE PRILLS(91,95) gas has specificly-response, to realize the highly selective and anti-interference of device, solves existingThe poor problem of formaldehyde sensor stability, selectivity in technology.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of transistor-type formaldehyde sensor of the present invention.
Fig. 2 is the preferred embodiment flow chart of the production method of transistor-type formaldehyde sensor of the present invention.
Specific embodiment
The present invention provides a kind of transistor-type formaldehyde sensor and preparation method thereof, to make the purpose of the present invention, technical sideCase and effect are clearer, clear, and the present invention is described in more detail below.It should be appreciated that specific reality described hereinIt applies example to be only used to explain the present invention, be not intended to limit the present invention.
A kind of transistor-type formaldehyde sensor, is adapted to detect for formaldehyde, wherein as shown in Figure 1, existing including substrate 100, settingGate electrode 200 in the substrate 100, is arranged in the dielectric layer 300 dielectric layer 300 being arranged on the gate electrode 200On laminated film 400, the source electrode 500 that is arranged on the laminated film 400 and drain electrode 600, the laminated film 400For the zinc-oxide film 401 for being adsorbed with metal nanoparticle 402.Transistor-type formaldehyde sensor of the present invention, in dielectricSetting is adsorbed with the zinc-oxide film of metal nanoparticle between layer and source/drain electrode, and the metal modified on zinc-oxide film is receivedRice grain PARA FORMALDEHYDE PRILLS(91,95) gas has specificly-response effect, and the laminated film PARA FORMALDEHYDE PRILLS(91,95) gas is enabled to make specific soundIt answers, so that device generates the variation of source-drain current when detecting formaldehyde gas, thus achieve the effect that sensing, Ye JiteDetect formaldehyde gas to opposite sex identification.
Preferably, in the transistor-type formaldehyde sensor, in the laminated film 400, metal nanoparticle 402 is logicalElectrostatic Absorption is crossed on zinc-oxide film 401.Metal nanoparticle can either be fixed on zinc oxide films by the suction-operated of electrostaticOn film, without being modified to metal nanoparticle or being fixed by the way that other groups are added, received so as to avoid to metalThe destruction of the performance of rice grain specificly-response formaldehyde gas.
The metal nanoparticle 402 being adsorbed on zinc-oxide film 401 can be gold nano grain, silver nano-grainThere is the metal nanoparticle of sensitive specificly-response performance with PARA FORMALDEHYDE PRILLS(91,95)s gases such as Pt nanoparticles.
Preferably, institute's zinc-oxide film 401 is made of the zinc oxide through alkali metal element doping vario-property, namely first passes through alkaliMetal-doped modification is used to make the zinc oxide of zinc-oxide film, and the field effect mobility of zinc oxide can be improved in the doping of alkali metalRate, so that the performance for the FET transistor being prepared is more preferably.
It is highly preferred that in the zinc-oxide film modified by alkali-metal-doped, alkali metal element and zinc oxide rubYou than being 0.01:1 ~ 0.15:1, the performance of the FET transistor being prepared it is further preferred that.
In the transistor-type formaldehyde sensor, the substrate 100 is flexible substrates, and the gate electrode 200 is metalGate electrode and the dielectric layer 300 are aluminum oxide dielectric layer, and the laminated film 400 also has flexibility, so that entirelyDevice all have fabulous flex capability, it can be achieved that device high mechanicalness.
The performance of transistor-type formaldehyde sensor of the present invention can pass through metal nanoparticle type, zinc oxideDoping concentration, aluminum oxide dielectric layer thickness, laminated film thickness and parameters various combination be adjusted.
Preferably, the flexible substrates are PDMS substrate；The gate electrode is silver metal gate electrode；The dielectric layer 30 is receivedThe thick alumina layer of rice；The zinc oxide nano film is 30 nanometer thickness zinc oxide nano films of alkali-metal-doped, and is utilized moltenThe method of liquid spin coating is prepared in substrate, then by metal nanoparticle Electrostatic Absorption on film；The source/drain electrode of gold will lead toMask is crossed to be deposited on laminated film.
It is highly preferred that the source/drain electrode channel length of the gold is 50 microns, width is 1000 microns, preparedThe sensor electric property that arrives it is further preferred that.
The present invention also provides a kind of production methods of transistor-type formaldehyde sensor, as shown in Figure 2, wherein including stepIt is rapid:
S1, substrate is provided, and forms gate electrode on the substrate；
S2, deposition prepares dielectric layer on the gate electrode；
S3, burnett's solution is provided, on the dielectric layer by burnett's solution coating, annealing forms zinc-oxide film；
S4, metal nanoparticle is provided, and electrification modification is carried out to zinc-oxide film, metal nanoparticle is then passed through into electrostaticEffect is adsorbed on zinc-oxide film, obtains laminated film；
S5, deposition forms source electrode and drain electrode on laminated film, obtains transistor-type formaldehyde sensor.
Preferably, in the step S1, by the metal of 20-30nm such as Ag etc. with the speed of 0.1nm/s 10-6Torr's is trueIt is vaporized in the form of thermal evaporation on flexible substrates such as PDMS under reciprocal of duty cycle, forms gate electrode.
In the step S2, by atomic layer deposition method, deposition of aluminium oxide prepares dielectric layer on the gate electrode.It is preferred thatGround, the aluminum oxide dielectric layer is with a thickness of 30nm.
It in the step S3, needs first to prepare burnett's solution, be prepared preferably by solwution method, be fabricated to reducingThis, specific steps are as follows: zinc oxide is dissolved in ammonium hydroxide and is refrigerated 5 hours, to increase the solubility of zinc oxide, then by instituteIt states burnett's solution spin coating on the dielectric layer, anneals, zinc-oxide film can be formed.Further, zinc-oxide film spin coating speedRate is 3000rpm, and spin-coating time 30s, annealing temperature is 200 DEG C, and annealing time is 0.5 hour.
Preferably, zinc-oxide film is controlled with a thickness of 30nm.
It is highly preferred that alkali metal hydroxide can be added in burnett's solution in the step S3, to realize to oxidationThe hydroxide of deionized water and lithium, sodium, potassium etc. is specifically added in burnett's solution by the doping vario-property of zinc, improves oxygenChange the field-effect mobility of zinc.Wherein it is possible to control addition alkali metal hydroxide and zinc oxide molar ratio be 0.01:1 ~0.15:1.
In the step S4, metal nanoparticle is first prepared, and electrification modification is carried out to the aluminum oxide film in step S3,In order to which metal nano-particle to be adsorbed on zinc-oxide film by electrostatic interaction, to be prepared with metal nanoparticleLaminated film, the step carries out electrification modification to zinc-oxide film, comprising: utilizes 3- aminopropyl triethoxysilane solutionImmersion treatment is carried out to zinc-oxide film, then by the zinc-oxide film after toluene rinse immersion treatment, then in nitrogen atmosphereMiddle drying.The 3- aminopropyl triethoxysilane solution is the toluene solution of 3- aminopropyl triethoxysilane, to zinc oxideAfter film impregnates 45mins, three times, extra unreacted 3- aminopropyl triethoxysilane point is being rinsed out using toluene rinseThen entire device is placed in drying under nitrogen environment, completes the on-line treatment of zinc-oxide film by son；Entire device is impregnated againThe 12h in metal nanoparticle solution, at this point, because electrostatic is had on zinc-oxide film, thus metal nanoparticle can pass throughThe effect of electrostatic is adsorbed on zinc-oxide film, is formed target laminated film, that is, is had the zinc-oxide film of metal nanoparticle.
The metal nanoparticle is one of gold nano grain, silver nano-grain and Pt nanoparticle or a variety of；InstituteGold nano grain is stated to be heated to 100 DEG C by tetra chlorauric acid solution and be added after sodium citrate reacts 10 ~ 60 minutes (such as 30 minutes)It is cooled to room temperature obtained, wherein preferably, the molar ratio of sodium citrate and tetra chlorauric acid is 3.78:1；The silver nanoparticleGrain is mixed by sodium citrate and silver nitrate and sodium borohydride reaction is added and is cooled to room temperature after (such as 30 minutes) for 10 ~ 60 minutesIt arrives, wherein preferably, the molar ratio of sodium citrate and silver nitrate is 3.78:1；The Pt nanoparticle by sodium citrate andPlatinum quaternary salts mix and sodium borohydride reaction are added and are cooled to room temperature to obtain after (such as 30 minutes) for 10 ~ 60 minutes, wherein preferablyThe molar ratio of ground, sodium citrate and platinum quaternary salts is 3.78:1.
In the step S5, by mask by the metal of 20-30nm such as Au etc. with the speed of 0.1nm/s in 10-6TorrVacuum degree under be vaporized in the form of thermal evaporation on the laminated film, form source electrode and drain electrode, it is sorrowful to obtain crystalline substanceBody cast formaldehyde sensor.Preferably, the source/drain electrode channel length for controlling the gold is 50 microns, and width is 1000 micro-Rice, preparation-obtained sensor electric property it is further preferred that.
It elaborates below by specific embodiment to the present invention:
Embodiment 1
Silver is formed into gate electrode by mask plate in the form of thermal evaporation on flexible PDMS substrate, passes through atomic layer deposition method30 nanometer thickness aluminum oxide dielectric layers are prepared on gate electrode；
Zinc oxide is dissolved in ammonium hydroxide and is refrigerated 5 hours, then the hydroxide of deionized water and lithium, sodium, potassium is added toIn burnett's solution, the molar ratio of the alkali metal hydroxide and zinc oxide that are added herein is 0.1:1, before obtaining zinc-oxide filmDrive liquid solution.On the dielectric layer by the spin coating of zinc-oxide film precursor solution, spin coating revolving speed is 3000rpm, time 30s, 200DEG C annealing 0.5h to get Nano zinc oxide film；
Tetra chlorauric acid solution is heated to 100 DEG C, sodium citrate is added, the molar ratio of sodium citrate and tetra chlorauric acid is herein3.78:1, reaction persistently carry out 30 minutes, and last solution is cooled to room temperature to arrive nanogold particle.To zinc-oxide film tableFace carries out electrification modification, and by the nanogold particle being prepared by Electrostatic Absorption on zinc-oxide film to get arriving nanometerGold particle-zinc oxide laminated film.
Gold is deposited on laminated film by mask and forms source/drain electrode, channel length is 50 microns, and width is1000 microns, finally obtain transistor-type formaldehyde sensor.
Embodiment 2
Silver is formed into gate electrode by mask plate in the form of thermal evaporation on flexible PDMS substrate, passes through atomic layer deposition method30 nanometer thickness aluminum oxide dielectric layers are prepared on gate electrode；
Zinc oxide is dissolved in ammonium hydroxide and is refrigerated 5 hours, then the hydroxide of deionized water and lithium, sodium, potassium is added toIn burnett's solution, the molar ratio of the alkali metal hydroxide and zinc oxide that are added herein is 0.01:1, obtains zinc-oxide filmPrecursor solution.On the dielectric layer by the spin coating of zinc-oxide film precursor solution, spin coating revolving speed be 3000rpm, time 30s,200 DEG C of annealing 0.5h are to get Nano zinc oxide film；
At room temperature, sodium citrate and silver nitrate are mixed and stirred for, the molar ratio of sodium citrate and silver nitrate is 3.78:1, soAfter be added immediately sodium borohydride, reaction persistently carries out 20 minutes, and last solution is cooled to room temperature to get to nano-Ag particles.It is rightZinc oxide films film surface carries out electrification modification, and the nano-Ag particles being prepared are passed through Electrostatic Absorption in zinc-oxide filmOn to get arrive nano-Ag particles-zinc oxide laminated film；
Gold is deposited on laminated film by mask and forms source/drain electrode, channel length is 50 microns, and width is 1000 micro-Rice, finally obtains transistor-type formaldehyde sensor.
Embodiment 3
Silver is formed into gate electrode by mask plate in the form of thermal evaporation on flexible PDMS substrate, passes through atomic layer deposition method30 nanometer thickness aluminum oxide dielectric layers are prepared on gate electrode；
Zinc oxide is dissolved in ammonium hydroxide and is refrigerated 5 hours, then the hydroxide of deionized water and lithium, sodium, potassium is added toIn burnett's solution, the molar ratio of the alkali metal hydroxide and zinc oxide that are added herein is 0.15:1, obtains zinc-oxide filmPrecursor solution.On the dielectric layer by the spin coating of zinc-oxide film precursor solution, spin coating revolving speed be 3000rpm, time 30s,200 DEG C of annealing 0.5h are to get Nano zinc oxide film；
At room temperature, sodium citrate and platinum quaternary salts are mixed and stirred for, the molar ratio of sodium citrate and platinum quaternary salts is 3.78:1, it is then added immediately sodium borohydride, reaction persistently carries out 60 minutes, and last solution is cooled to room temperature to arrive Platinum NanoparticlesGrain.Electrification modification is carried out to zinc oxide films film surface, and the nano-platinum particle being prepared is passed through into Electrostatic Absorption in zinc oxideOn film to get arrive nano-platinum particle-zinc oxide laminated film；
Gold is deposited on laminated film by mask and forms source/drain electrode, channel length is 50 microns, and width is 1000 micro-Rice, finally obtains transistor-type formaldehyde sensor.
Embodiment 4
The sensor prepared in embodiment 1 ~ 3 is placed in gas test chamber, grid, source electrode and the leakage of probe contactor partPole is passed through the source-drain current variation of certain density formaldehyde test transistor device, the results show that source-drain current is changed significantly,I.e. preparation-obtained transistor-type formaldehyde sensor being capable of specificly-response formaldehyde gas.
Embodiment 5
Resist bending test is carried out to sensor prepared in embodiment 1 ~ 3, method particularly includes: it is gentle with Linmot linear motorDynamic vibration platform builds sample drawing stand, carries out the test of the fatigue behaviour and environmental stability of flexible sensor.In compression repeatedlyWith tensile means by the circulation of the order of magnitude and then the electrical performance testing of progress flexible sensor.The results show that of the inventionThe transistor-type formaldehyde sensor of preparation still maintains good electric property, has fabulous through Repeated Compression and after stretchingFlex capability, it can be achieved that device high mechanicalness.
In conclusion transistor-type formaldehyde sensor provided by the invention, by the way that laminated film is arranged on the dielectric layer, soSource electrode and drain electrode are set on the laminated film again afterwards, are adsorbed with the zinc-oxide film of metal nanoparticle, THIN COMPOSITEFilm can change carrier concentration, surface state and the device transport capacity of transistor, and due to the modification of metal nanoparticle, makeObtaining laminated film PARA FORMALDEHYDE PRILLS(91,95) gas has specificly-response, to realize the highly selective and anti-interference of device, solves existingThe poor problem of formaldehyde sensor stability, selectivity in technology.
It should be understood that the application of the present invention is not limited to the above for those of ordinary skills canWith improvement or transformation based on the above description, all these modifications and variations all should belong to the guarantor of appended claims of the present inventionProtect range.