CN112858440A - Schottky diode hydrogen sensor core - Google Patents

Schottky diode hydrogen sensor core Download PDF

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CN112858440A
CN112858440A CN202110155170.7A CN202110155170A CN112858440A CN 112858440 A CN112858440 A CN 112858440A CN 202110155170 A CN202110155170 A CN 202110155170A CN 112858440 A CN112858440 A CN 112858440A
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方海涛
李瑞武
李思佳
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Harbin Institute of Technology
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    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
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    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

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Abstract

The invention relates to a Schottky diode hydrogen sensor core body. The Schottky diode hydrogen sensor core body is composed of a four-layer structure and a conductive lead, wherein the four-layer structure comprises a hydrogen cracking metal layer, a hydroxyl diffusion barrier layer, a semiconductor layer and a current collector layer in sequence, and the conductive lead is respectively led out from the hydrogen cracking metal layer and the current collector layer. The Schottky diode hydrogen sensor core body has the special performance of resisting humidity interference at room temperature, the sensitivity of the Schottky diode hydrogen sensor core body to hydrogen cannot be reduced by water vapor in a gas environment at room temperature, and the defect that the humidity of the existing common hydrogen cracking metal layer/semiconductor layer Schottky diode hydrogen sensor core body without a hydroxyl diffusion barrier layer reduces the hydrogen sensitivity of the Schottky diode hydrogen sensor core body at room temperature is overcome.

Description

Schottky diode hydrogen sensor core
Technical Field
The invention belongs to the technical field of hydrogen sensors, and particularly relates to a Schottky diode hydrogen sensor core.
Background
As a high-efficiency clean fuel, the hydrogen has the advantages of high energy storage density, no pollution and the like, is an ideal clean energy and is widely concerned. Hydrogen, as a reducing gas and carrier gas, has been used in the fields of petrochemistry, medical treatment, electronics, aircraft rocket launching, petroleum refining, metal welding, cryogenic cooling, chemical synthesis, and the like. However, hydrogen gas is very small and is easy to leak during production, transportation and use. When the content of hydrogen in the air is 4-74.4%, explosion can occur when exposed to fire. Therefore, the rapid and effective leakage detection in the hydrogen storage and use process is very important for the safe use of hydrogen, and the research of the reliable hydrogen sensor with high sensitivity has great significance.
Researchers have endeavored to design and manufacture hydrogen sensors with high sensitivity, fast response speed, good selectivity, high stability, small influence of humidity, simple manufacturing process, low price and easy integration. In recent years, research on hydrogen sensors at home and abroad has been mainly focused on hydrogen sensors of semiconductor type, thermoelectric type, optical type, electrochemical type, and the like. The sensitivity responsiveness, interference immunity etc. of the hydrogen sensor core determine the working performance of the hydrogen sensor.
The hydrogen sensor based on the Schottky diode core has the advantages of good selectivity, high sensitivity, wide response dynamic range, low power consumption, high switching speed, simple control circuit and the like, and great research interest of researchers is aroused. The core of the current schottky diode hydrogen sensor is composed of a hydrogen splitting metal layer-semiconductor layer. Various environmental factors have a large impact on the performance of schottky diode hydrogen sensors. It should be particularly noted that the water vapor in the atmospheric environment at room temperature has a great adverse effect on the hydrogen sensitivity of the schottky diode hydrogen sensor, and the humidity can greatly reduce the hydrogen sensitivity of the schottky diode hydrogen sensitive core of the common hydrogen cracking metal layer-semiconductor structure. The temperature rise can solve the adverse effect of humidity on hydrogen sensitivity, but increases energy consumption, and is easy to trigger the rapid reaction of hydrogen and oxygen, thereby bringing new potential safety hazard. The performance of reducing hydrogen sensitivity by humidity at room temperature is a difficult problem in the practical application of the prior Schottky diode hydrogen sensor. It is a necessary and urgent problem to solve to weaken or eliminate the adverse effect of humidity on the room temperature hydrogen sensitivity of the hydrogen sensitive core of the schottky diode by a proper method.
Disclosure of Invention
The invention aims to obtain a Schottky diode hydrogen sensor core body with room-temperature hydrogen sensitivity not influenced or slightly influenced by air humidity.
The invention provides a novel Schottky diode hydrogen sensor core body, aiming at solving the technical problem that the application of the Schottky diode hydrogen sensor is limited due to the defect that the humidity of the existing Schottky diode hydrogen sensor core body can reduce the hydrogen sensitivity performance at room temperature.
The invention provides a Schottky diode hydrogen sensor core body which is composed of a four-layer structure and a conductive lead, wherein the four-layer structure sequentially comprises a hydrogen cracking metal layer, a hydroxyl diffusion barrier layer, a semiconductor layer and a current collector layer.
Preferably, the conductive leads are led out from the hydrogen-splitting metal layer and the current collector layer, respectively.
Preferably, the material adopted by the hydroxyl diffusion barrier layer is one or more of graphene oxide, graphene, boron nitride, silicon nitride, germanium nitride, transition metal boride, transition metal sulfide, transition metal selenide, transition metal antimonide and a composite material formed between the two or more of the two.
Preferably, the hydrogen-cracking metal layer is made of one or more of platinum, palladium, ruthenium, nickel, iridium, cobalt and alloys formed between two or more of the platinum, palladium, ruthenium, nickel, iridium and cobalt.
Preferably, the material adopted by the semiconductor layer is one or more of titanium oxide, tin oxide, zinc oxide, tungsten oxide, copper oxide, iron oxide, cobalt oxide, nickel oxide, molybdenum oxide, silicon, gallium oxide, hafnium oxide, indium oxide, tantalum oxide, cadmium oxide, niobium oxide and composite oxides and multi-element oxides formed between two or more of the two.
Preferably, the current collector layer is a metal conductor layer or a conductive coating.
The core structure of the common Schottky diode hydrogen sensor and the hydrogen sensitive principle are as follows: the core body of the common Schottky diode hydrogen sensor generally comprises a three-layer structure and conductive leads, wherein the three-layer structure sequentially comprises a hydrogen cracking metal layer, a semiconductor layer and a current collector layer, and the conductive leads are respectively led out from the hydrogen cracking metal layer and the current collector layer; the hydrogen cracking metal layer/semiconductor layer forms a Schottky barrier and has one-way conductivity, when the Schottky barrier is contacted with hydrogen, hydrogen molecules are adsorbed on the surface of the hydrogen cracking metal layer, and because the hydrogen cracking metal layer has the capability of catalyzing and cracking the hydrogen molecules into hydrogen atoms, the hydrogen molecule adsorption layer is converted into a hydrogen atom adsorption layer, and then the adsorbed hydrogen atoms are diffused into crystal lattices of the hydrogen cracking metal layer to form a solid solution of solid-dissolved hydrogen atoms, the process can reduce the work function of the hydrogen cracking metal layer, so that the Schottky barrier at the interface of the hydrogen cracking metal layer/semiconductor layer is reduced, the turn-on voltage of the Schottky diode hydrogen sensor core is reduced, if the Schottky diode hydrogen sensor core is kept at a certain constant voltage, the turn-on voltage is reduced, so that the current passing through the Schottky diode hydrogen sensor core is increased, thereby realizing sensitive detection of hydrogen.
Compared with the prior art, the invention at least has the following beneficial effects: the Schottky diode hydrogen sensor core body has excellent humidity interference resistance, overcomes the defect that the hydrogen sensitivity of the conventional common Schottky diode hydrogen sensor core body is greatly reduced by ambient water vapor at room temperature, and only slightly reduces the hydrogen sensitivity of the Schottky diode hydrogen sensor core body at room temperature by the ambient water vapor, wherein the reduction amplitude is not more than 8%.
The principle of achieving the above advantageous effects is as follows. The surface of the metal oxide semiconductor or the surface oxide layer of the non-metal oxide semiconductor can catalytically decompose water molecules, then a large number of hydroxyl groups are formed with oxygen atoms, the hydroxyl groups migrate to the surface of the hydrogen cracking metal layer and react with adsorbed hydrogen to consume a large number of adsorbed hydrogen, so that the work function of the hydrogen cracking metal layer is reduced, and the hydrogen sensitive performance of the common Schottky diode hydrogen sensor with the hydrogen cracking metal layer/semiconductor layer structure is reduced due to the fact that humidity at room temperature is reduced; the hydroxyl diffusion barrier layer is introduced between the hydrogen cracking metal layer and the semiconductor layer, so that hydroxyl generated by water molecules and oxygen on the surface of the semiconductor layer cannot diffuse to the surface of the hydrogen cracking metal layer, namely the hydroxyl diffusion barrier layer effectively prevents the diffusion of the hydroxyl generated by the reaction of the oxygen and the water molecules on the surface of the semiconductor layer to the surface of the hydrogen cracking metal layer, thereby avoiding the consumption of hydrogen adsorbed on the surface of the hydrogen cracking metal layer by the hydroxyl, further solving the problem of sensitivity reduction caused by the consumption of the hydrogen adsorbed on the hydrogen cracking metal layer, and finally ensuring that the ambient humidity at room temperature is not reduced or is only reduced in a small way (the reduction amplitude is not more than 8 percent).
Drawings
Fig. 1 is a schematic structural diagram of a schottky diode hydrogen sensor core according to the present invention. The drawings are provided for illustrative purposes only, and the proportions and dimensions of the layers in the drawings do not necessarily correspond to those of an actual product.
In fig. 1: 1: a conductive lead; 2: hydrogen cracking the metal layer; 3: a hydroxyl diffusion barrier layer; 4: a semiconductor layer; 5: a current collector layer.
FIG. 2 shows Pt-TiO in comparative example 12The current-voltage characteristic (I-V characteristic) curve and the current-time change (I-t characteristic) curve of the Schottky diode hydrogen sensor core body at room temperature. In the figure, (a) is Pt-TiO2The I-V characteristic curve of the Schottky diode hydrogen sensor core body in the dry air (mixed gas of high-purity nitrogen and high-purity oxygen in a volume ratio of 4: 1) environment can be known from the figure, and Pt-TiO2The schottky diode hydrogen sensor core body shows one-way conductivity, and the starting voltage of the schottky diode hydrogen sensor core body is 0.85V. In the figure, (b) and (c) are respectively Pt-TiO2The core body of the Schottky diode hydrogen sensor has I-t characteristic curves under a dry air environment and an air environment with the relative humidity of 95%, the test temperature is room temperature, the applied bias voltage is 0.85V during the test, and the tested hydrogen concentration is 1000ppm (namely hydrogen and dry air are mixed according to the volume ratio of 1: 1000). In the figure, the ordinate is current in a (ampere), the abscissa is voltage in V (volt), the abscissas of (b) and (c) are time in s (second), and the abscissa is response current in a (ampere).
FIG. 3 shows Pt-GO-TiO of example 12Volt-ampere (I-V) characteristic curve of Schottky diode hydrogen sensor core at room temperatureLine and current (I-t) characteristics over time, GO represents the graphene oxide layer. In the figure, (a) is Pt-GO-TiO2The I-V characteristic curve of the Schottky diode hydrogen sensor core body in a dry air environment can be known from the figure, and Pt-GO-TiO2The schottky diode hydrogen sensor core exhibits one-way conductivity with a 0.83V turn-on voltage. In the figure, (b) and (c) are respectively Pt-GO-TiO2The core body of the Schottky diode hydrogen sensor has I-t characteristic curves in a dry air environment (a mixed gas of high-purity nitrogen and high-purity oxygen in a volume ratio of 4: 1) and an air environment with a relative humidity of 95%, the test temperature is room temperature, the applied bias voltage is 0.83V during the test, and the tested hydrogen concentration is 1000ppm (namely, hydrogen and dry air are mixed in a volume ratio of 1: 1000). In the figure, the ordinate is current in a (ampere), the abscissa is voltage in V (volt), the abscissas of (b) and (c) are time in s (second), and the abscissa is response current in a (ampere).
Specifically, the hydrogen response sensitivity of the hydrogen sensor core under forward bias tends to increase and then decrease with increasing bias, i.e., there is an optimum bias to maximize the sensitivity of the hydrogen sensor core. In the embodiment of the invention, the bias voltage selected for testing the hydrogen sensitivity performance is the positive starting voltage of the core body of the hydrogen sensor in dry air.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The invention provides a schottky diode hydrogen sensor core body with humidity resistance, for example, as shown in fig. 1, fig. 1 is a schematic structural diagram of the schottky diode hydrogen sensor core body of the invention.
In the invention, the Schottky diode hydrogen sensor core body is composed of a four-layer structure and a conductive lead, wherein the four-layer structure sequentially comprises a hydrogen cracking metal layer 2, a hydroxyl diffusion barrier layer 3, a semiconductor layer 4 and a current collector layer 5. In the present invention, the hydrogen dissociation metal layer 2, the hydroxyl diffusion barrier layer 3, the semiconductor layer 4, and the current collector layer 5 are sequentially stacked from top to bottom or from bottom to top. In the present invention, the conductive leads 1 are led out from the hydrogen-splitting metal layer 2 and the current collector layer 5, respectively. In the present invention, the schottky diode hydrogen sensor core is also referred to as a schottky diode hydrogen sensor core or a hydrogen-splitting metal layer-hydroxyl diffusion barrier layer-semiconductor type schottky diode hydrogen sensor core.
The Schottky diode hydrogen sensor core body has excellent humidity interference resistance at room temperature (for example, the room temperature is 10-30 ℃), can ensure that the hydrogen sensor is applied to a humid atmospheric environment at room temperature, and has a wide application range.
According to some preferred embodiments, the conductive leads 1 are respectively led out from the hydrogen-splitting metal layer 2 and the current collector layer 5; in the present invention, the conductive lead 1 may be made of, for example, a copper wire.
According to some preferred embodiments, the hydroxyl diffusion barrier layer is made of one or more of graphene oxide, graphene, boron nitride, silicon nitride, germanium nitride, transition metal boride, transition metal sulfide, transition metal selenide, transition metal antimonide, and a composite material formed between two or more of the above materials. The inventor finds that the hydroxyl diffusion barrier layer can prevent hydroxyl generated by reaction of water molecules and oxygen on the surface of the semiconductor layer from diffusing to the surface of the hydrogen cracking metal layer, can remarkably inhibit adverse effects of ambient humidity at room temperature on the hydrogen sensitivity of the Schottky diode hydrogen sensor core, and ensures that the ambient humidity at room temperature is not reduced or is only reduced slightly (the reduction amplitude is not more than 8 percent) on the sensitivity of the Schottky diode hydrogen sensor core to hydrogen.
According to some preferred embodiments, the hydrogen-splitting metal layer is made of one or more of platinum, palladium, ruthenium, nickel, iridium, cobalt and alloys formed between two or more of the platinum, palladium, ruthenium, nickel, iridium and cobalt.
According to some preferred embodiments, the semiconductor layer is made of one or more of titanium oxide, tin oxide, zinc oxide, tungsten oxide, copper oxide, iron oxide, cobalt oxide, nickel oxide, molybdenum oxide, silicon, gallium oxide, hafnium oxide, indium oxide, tantalum oxide, cadmium oxide, niobium oxide, and composite oxides and multi-component oxides formed between or between the two.
According to some preferred embodiments, the current collector layer is a metal conductor layer or a conductive coating.
The present invention will be further described with reference to the following examples. These examples are merely illustrative of preferred embodiments of the present invention and the scope of the present invention should not be construed as being limited to these examples.
Example 1
Firstly, cutting a metal titanium sheet, deoiling, placing in a tube furnace, oxidizing for 2h at 680 ℃ in air atmosphere, and preparing titanium dioxide (TiO) on the surface of the titanium sheet2) A semiconductor layer.
② ultrasonic dispersing 75mg Graphite Oxide (GO) powder in 150mL absolute ethyl alcohol to obtain 0.5mg/mL graphene oxide-ethanol dispersion, adding GO-ethanol dispersion into an electrophoresis cell until there is TiO on the surface2Depositing graphene oxide on TiO under the conditions of deposition voltage of 50V and deposition time of 60min by using a titanium sheet of a semiconductor layer as an electrophoresis anode and an inert metal sheet or graphite sheet as an electrophoresis cathode2The surface of the semiconductor layer.
Thirdly, a platinum (Pt) target with the purity of 99.99 percent (mass fraction) is arranged at a cathode target position of a magnetron sputtering system, the sample obtained in the 2 steps is placed in a cavity, and the surface of the graphene oxide layer is subjected to electromagnetic sputtering Pt plating to obtain a hydrogen cracking metal Pt layer.
Fourthly, TiO is added2Polishing the surface of the semiconductor layer without the deposited graphene oxide layer with fine abrasive paper to remove TiO2The layer enables metal Ti to leak out, the metal Ti substrate serves as a current collector layer, and then a thin copper wire (a conductive lead) is glued on the metal Ti current collector layer through conductive silver to serve as a core body cathode; and a thin copper wire (a conductive lead) is led out from the hydrogen cracking metal Pt layer and is used as the positive electrode of the core body.
Preparing a hydrogen splitting metal layer-hydroxyl diffusion barrier layer-semiconductor layer Schottky diode hydrogen sensor core marked as Pt-GO-TiO by the 4 steps2The Schottky diode hydrogen sensor core body has the graphene oxide layer serving as a hydroxyl diffusion barrier layer.
Example 2
Firstly, a piece of aluminum foil is cut out to serve as a current collector layer, metal tungsten (W) is used as a target material by adopting a magnetron sputtering method, and tungsten trioxide (WO) is deposited on one surface of the aluminum foil by using mixed gas of argon and oxygen (W)3) Film to obtain WO3A semiconductor layer.
② ultrasonically dispersing 30mg of boron nitride nanosheet in 300mL of isopropanol to obtain boron nitride dispersion liquid, and dropwise adding 1mL of boron nitride nanosheet ethanol dispersion liquid in WO3And obtaining the boron nitride layer capable of blocking the diffusion of the hydroxyl on the surface of the semiconductor layer.
Thirdly, a palladium (Pd) target with the purity of 99.99 percent (mass fraction) is arranged at a cathode target position of a magnetron sputtering system, the sample obtained in the 2 steps is placed in a cavity, and Pd is sputtered and plated on the surface of the boron nitride layer, so that a hydrogen cracking metal Pd layer is obtained.
Fourthly, adhering the thin copper wire (conductive lead) to the non-deposited WO on the Al current collector through the conductive silver glue3As a core negative electrode; and a thin copper wire (a conductive lead) is led out from the hydrogen cracking metal Pd layer and is used as the positive electrode of the core body.
Preparing a hydrogen splitting metal layer-hydroxyl diffusion barrier layer-semiconductor type Schottky diode hydrogen sensor core, which is recorded as Pd-BN-WO, through the 4 steps3The Schottky diode hydrogen sensor core body is characterized in that the boron nitride layer is a hydroxyl diffusion barrier layer.
Example 3
Firstly, a piece of Cu foil is cut out to serve as a current collector layer, metal tin (Sn) is used as a target material by adopting a magnetron sputtering method, and argon and oxygen are usedGas mixture, and depositing tin dioxide (SnO) on one surface of the aluminum foil2) Thin film to obtain SnO2A semiconductor layer.
② in SnO2And depositing silicon nitride on the surface of the semiconductor layer by a magnetron sputtering method to obtain a silicon nitride layer capable of blocking hydroxyl diffusion.
Thirdly, a platinum-iridium alloy (Pt-Ir) target with the purity of 99.99 percent (mass fraction) is arranged at a cathode target position of a magnetron sputtering system, and the sample obtained in the 2 steps is placed in a cavity for SnO2And sputtering and plating platinum-iridium alloy on the surface of the layer to obtain a hydrogen cracking platinum-iridium alloy layer.
Finally, gluing thin copper wires (conductive leads) on the Cu current collector through conductive silver glue without SnO deposition2As a core negative electrode; thin copper wires (conductive leads) are led out of the hydrogen cracking platinum-iridium alloy layer by layer and serve as the positive electrode of the core body.
Preparing a hydrogen splitting metal layer-hydroxyl diffusion barrier layer-semiconductor type Schottky diode hydrogen sensor core, which is marked as PtIr-Si, through the 4 steps3N4-SnO2The Schottky diode hydrogen sensor core body and the silicon nitride layer are hydroxyl diffusion barrier layers.
Comparative example 1
Firstly, cutting a metal titanium sheet, deoiling, placing in a tube furnace, oxidizing for 2h at 680 ℃ in air atmosphere, and preparing titanium dioxide (TiO) on the surface of the titanium sheet2) A semiconductor layer.
Secondly, a platinum (Pt) target with the purity of 99.99 percent (mass fraction) is arranged at a cathode target position of a magnetron sputtering system, and the sample obtained in the step is placed in a cavity for TiO2And performing electromagnetic sputtering Pt plating on the surface of the layer to obtain a hydrogen cracking metal Pt layer.
Thirdly, polishing the surface without depositing the Pt layer by using fine sand paper to polish the TiO on the surface2The layer enables metal Ti to leak out, the metal Ti substrate serves as a current collector layer, and then a thin copper wire (a conductive lead) is glued on the metal Ti current collector layer through conductive silver to serve as a core body cathode; and a thin copper wire (a conductive lead) is led out from the hydrogen cracking metal Pt layer and is used as the positive electrode of the core body.
In comparative example 1, positive and negative electrodesLeading out to obtain the hydrogen splitting metal layer/semiconductor Schottky diode hydrogen sensor core body which is marked as Pt-TiO2Schottky diode hydrogen sensor cores.
The Schottky diode Hydrogen sensor cores of example 1 and comparative example 1 are respectively labeled as Pt-GO-TiO2And Pt-TiO2The only difference is the presence or absence of a graphene oxide layer on the hydrogen-splitting metal Pt layer and TiO2Between the semiconductor layers, it acts as a hydroxyl diffusion barrier.
The invention respectively tests Pt-GO-TiO2And Pt-TiO2Sensitivity to 1000ppm hydrogen at room temperature under ambient conditions of dryness (i.e. no humidity) and 95% humidity.
Before testing the sensitivity, Pt-TiO is tested in dry air (mixed gas of high-purity nitrogen and high-purity oxygen in a volume ratio of 4: 1)2And Pt-GO-TiO2The current-voltage (I-V) characteristics at room temperature are shown in FIG. 2(a) and FIG. 3(a), respectively, from which Pt-TiO can be determined2And Pt-GO-TiO2Exhibit a unidirectional turn-on characteristic with a turn-on voltage of 0.85V and 0.83V, respectively. Then to Pt-TiO2Applying constant voltage of 0.85V to Pt-GO-TiO2A constant voltage of 0.83V was applied, and dry air was switched with 1000ppm hydrogen (hydrogen mixed with dry air at a volume ratio of 1: 1000) at room temperature, or air at 95% relative humidity was switched with 1000ppm hydrogen at room temperature while recording current-time (I-t) curves, and the results are shown in fig. 2(b), 2(c) and fig. 3(b), 3(c), respectively.
The sensitivity is the ratio of the highest response current after 1000ppm hydrogen was introduced to the reference current in air before 1000ppm hydrogen was introduced. From fig. 2(b) and 2(c) and fig. 3(b) and 3(c), the ground state current and the maximum response current before and after 1000ppm of hydrogen gas was introduced were known, and the sensitivity under different test conditions was calculated from the ratio of the maximum response current to the ground state current. Table 1 summarizes Pt-TiO2And Pt-GO-TiO2And the ground state current in dry air and air at 95% relative humidity and the highest response current to 1000ppm hydrogen, and the sensitivity is listed, it can be seen that 95% humidity will Pt-TiO2From 2.3 to 1.44, decreaseThe amplitude is as high as 37.4%, and the Pt-GO-TiO is subjected to 95% humidity2The sensitivity of (a) is reduced from 5.09 to 5.03 by only 1.2%. Pt-GO-TiO2And Pt-TiO2The contrast of shows, the sensitivity of schottky diode hydrogen sensor core has not only been improved to the oxidation graphite alkene layer, can also show the moisture interference resistance characteristic that promotes schottky diode hydrogen sensor core.
In the invention, the reason for improving the sensitivity of the Schottky diode hydrogen sensor core body is probably that the existence of the graphene oxide layer eliminates the influence of surface defects and microcracks of a semiconductor, can eliminate a pinning effect, reduce reverse leakage current, reduce interface state density, improve the rectification characteristic of the Schottky diode hydrogen sensor core body, and increase the change of a Schottky barrier caused by the change of a platinum work function after hydrogen is introduced, thereby improving the sensitivity.
Pt-GO-TiO2The graphene oxide barrier layer effectively prevents hydroxyl generated by reaction of oxygen and water molecules on the surface of the semiconductor layer from diffusing to the surface of a hydrogen cracking metal layer, can obviously inhibit the adverse effect of the hydrogen sensitivity performance reduction caused by the fact that the hydroxyl diffuses to the surface of a hydrogen sensitive layer and hydrogen is combined, and finally enables water vapor in ambient gas at room temperature not to greatly reduce the sensitivity of the Schottky diode hydrogen sensor core body to the hydrogen, and the 95% humidity at room temperature only causes the reduction of 1.2% of the sensitivity to the 1000ppm hydrogen. The hydrogen splitting metal layer-hydroxyl diffusion barrier layer-semiconductor Schottky diode hydrogen sensor core body is particularly suitable for being applied to a heating-free low-power-consumption room-temperature hydrogen sensor working in a humidity environment.
Table 1: sensitivity of the Schottky diode hydrogen sensor core body in the comparative example 1 and the Schottky diode hydrogen sensor core body in the example 1 under different gas environments.
Figure BDA0002933104680000101
Figure BDA0002933104680000111
Specifically, the relative humidity of 95% air in the present invention means that the moisture content in the air is 95%.
Finally, the description is as follows: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the embodiments can still be modified, or some technical features can be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the present invention in its spirit and scope.

Claims (6)

1. The utility model provides a schottky diode hydrogen sensor core which characterized in that:
the Schottky diode hydrogen sensor core body is composed of a four-layer structure and a conductive lead, wherein the four-layer structure sequentially comprises a hydrogen cracking metal layer, a hydroxyl diffusion barrier layer, a semiconductor layer and a current collector layer.
2. The schottky diode hydrogen sensor core of claim 1 wherein:
and the conductive leads are respectively led out from the hydrogen cracking metal layer and the current collector layer.
3. The schottky diode hydrogen sensor core of claim 1 wherein:
the hydroxyl diffusion barrier layer is made of one or more of graphene oxide, graphene, boron nitride, silicon nitride, germanium nitride, transition metal boride, transition metal sulfide, transition metal selenide, transition metal antimonide and composite materials formed between the two or more of the two.
4. The schottky diode hydrogen sensor core of claim 1 wherein:
the hydrogen cracking metal layer is made of one or more of platinum, palladium, ruthenium, nickel, iridium, cobalt and alloys formed between the platinum, the palladium, the ruthenium, the nickel, the iridium and the cobalt.
5. The schottky diode hydrogen sensor core of claim 1 wherein:
the semiconductor layer is made of one or more of titanium oxide, tin oxide, zinc oxide, tungsten oxide, copper oxide, iron oxide, cobalt oxide, nickel oxide, molybdenum oxide, silicon, gallium oxide, hafnium oxide, indium oxide, tantalum oxide, cadmium oxide, niobium oxide and composite oxides and multi-element oxides formed between the two or more.
6. The schottky diode hydrogen sensor core of claim 1 wherein:
the current collector layer is a metal conductor layer or a conductive coating.
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CN113358710A (en) * 2021-06-03 2021-09-07 吉林大学 Olivine structure gas-sensitive material for detecting formaldehyde and preparation method thereof
CN115825156A (en) * 2022-12-07 2023-03-21 武汉优斯特传感器科技有限公司 Core body structure of hydrogen sensor

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