An ultrafast hydrogen response sensing structure based on RC differential thin film circuit

Abstract

The present invention provides an ultrafast hydrogen response sensing structure based on an RC differential thin film circuit, belonging to the field of gas sensor technology. The structure comprises a thin film resistor hydrogen sensing unit, a voltage divider / heating thin film resistor, an RC differential thin film circuit, and four lead electrodes. The RC differential thin film circuit includes an RC differential thin film capacitor and an RC differential thin film resistor. The RC differential thin film capacitor comprises a first electrode, a dielectric layer, and a second electrode. The first lead electrode is connected to the first electrode via the voltage divider / heating thin film resistor; the second lead electrode is connected to the first electrode via the thin film resistor hydrogen sensing unit; the third lead electrode is a voltage output terminal connected to the second electrode; and the fourth lead electrode is connected to the second electrode via the RC differential thin film resistor. The present invention achieves rapid hydrogen response and concentration detection based on the peak occurrence time and peak value of the first-order derivative output curve, greatly improves the integration of the gas rapid response system, significantly reduces the system size and power consumption, and is suitable for scenarios with different hydrogen detection requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas sensors, and in particular relates to an ultrafast hydrogen response sensing structure based on an RC differential thin film circuit. Background Art

[0002] In recent years, with the development of the hydrogen energy industry, the safety issues surrounding hydrogen use have received increasing attention. Hydrogen, a flammable and explosive gas, has a wide explosive concentration range (the explosive limit in air is 4% to 75%). Its colorless and odorless nature makes it difficult for the human senses to detect. Therefore, real-time monitoring of hydrogen concentration in actual use scenarios has become an essential safety technology in hydrogen applications.

[0003] Existing hydrogen sensors, such as semiconductor metal oxide hydrogen sensors, offer advantages such as high sensitivity and low cost, and have been widely used in hydrogen applications such as new energy vehicles. However, existing semiconductor metal oxide hydrogen sensors have a slow response speed to hydrogen, making them difficult to meet the hydrogen detection needs in hazardous scenarios such as hydrogen leaks. Therefore, improving the response speed of hydrogen sensors is key to further advancing safety technologies in hydrogen applications.

[0004] The existing mainstream way to improve the response speed of hydrogen sensors is to analyze the hydrogen sensor response curve through back-end circuit and algorithm processing, and specifically analyze the characteristics of a small section of the curve after the start of the response to predict the final response size. For example, Chinese patent application number 202211628182.8 discloses a method for rapid prediction of hydrogen concentration based on CNN-LSTM (convolutional neural network-long short-term memory network). This method accelerates the prediction of hydrogen concentration by extracting the data characteristics of the initial stage of the first 30s response of the hydrogen sensor response-recovery curve. The above-mentioned method for improving the response speed of hydrogen sensors is relatively mature and widely used in existing hydrogen sensing systems. However, in the existing response acceleration scheme, the back-end algorithm for data reading and data processing needs to be equipped with complex peripheral circuits, which have problems such as high cost, large size, low integration, and high power consumption. It is often difficult to meet the needs of complex and changeable application scenarios, and its response speed is also subject to the complex algorithm processing process, which is still unsatisfactory. Therefore, it is necessary to seek a hydrogen sensing solution with higher integration, smaller size, lower power consumption and faster response speed. Summary of the Invention

[0005] To address the problems of long response time and high complexity of peripheral data processing circuits in existing hydrogen sensors, the present invention provides an ultrafast hydrogen response sensing structure based on RC differential thin-film circuits. This structure achieves sub-second response hydrogen concentration detection through thin-film circuits. It has high integration and has broad application potential in scenarios requiring hydrogen concentration detection, such as industrial production and new energy vehicles.

[0006] In order to achieve the above purpose, the technical methods adopted by the present invention are as follows:

[0007] An ultrafast hydrogen response sensing structure based on an RC differential thin film circuit includes a thin film resistor type hydrogen sensing unit, a voltage divider / heating thin film resistor, an RC differential thin film circuit, and four lead electrodes; the RC differential thin film circuit includes an RC differential thin film capacitor and an RC differential thin film resistor; the RC differential thin film capacitor includes a first electrode, a dielectric layer, and a second electrode;

[0008] Among them, the first lead electrode is connected to the first electrode through a voltage divider / heating thin film resistor; the second lead electrode is connected to the first electrode through a thin film resistor type hydrogen sensor unit; the third lead electrode is a voltage output end, connected to the second electrode; the fourth lead electrode is connected to the second electrode through an RC differential thin film resistor.

[0009] Furthermore, the voltage divider / heating thin film resistor is arranged around the thin film resistor type hydrogen sensor unit.

[0010] Furthermore, the RC differential film capacitor is an interdigital film capacitor or a planar film capacitor.

[0011] Furthermore, the first lead-out electrode is connected to a voltage source, and the second lead-out electrode and the fourth lead-out electrode are grounded.

[0012] Furthermore, the resistance ratio of the thin film resistor type hydrogen sensor unit to the pressure divider / heating thin film resistor is in the range of 0.1 to 10.

[0013] Furthermore, the thin film resistor type hydrogen sensing unit adopts a positive response hydrogen sensitive thin film resistor or a negative response hydrogen sensitive thin film resistor.

[0014] Furthermore, the thin film of the thin film resistance type hydrogen sensor unit is made of a single layer material or a layered composite material, specifically palladium metal, or an alloy formed by palladium and one or more metals selected from nickel, cobalt, gold, and ruthenium.

[0015] Furthermore, the voltage divider / heating thin film resistor, RC differential thin film resistor, first electrode, second electrode and four lead electrodes are made of gold, or a composite material consisting of gold and at least one other metal material, and the metal material is chromium or titanium.

[0016] Furthermore, the composite material is a layered stacked material or an alloy material.

[0017] Furthermore, the thickness of the thin film resistance type hydrogen sensor unit is 1 to 100 nm.

[0018] Furthermore, the thickness of the voltage divider / heating thin film resistor is 20-100 nm.

[0019] Furthermore, the thickness of the RC differential thin film resistor is 20-100 nm.

[0020] Furthermore, the thickness of the first electrode and the second electrode is 20-50 nm.

[0021] Furthermore, the material of the dielectric layer is aluminum oxide or silicon oxide.

[0022] Furthermore, the thickness of the dielectric layer is 50 nm.

[0023] Furthermore, the capacitance value of the RC differential thin film capacitor ranges from 1 nF to 1 μF, and is changed by adjusting the facing area and the distance between the first electrode and the second electrode, as well as the dielectric layer material.

[0024] Furthermore, the resistance value of the RC differential thin film resistor ranges from 1KΩ to 1MΩ, and is changed by adjusting the number of square resistors and the film thickness.

[0025] Furthermore, by adjusting the capacitance value of the RC differential thin film capacitor and the resistance value of the RC differential thin film resistor, the time constant of the RC differential thin film circuit is changed to control the response time and response size of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit.

[0026] Furthermore, the time constant ranges from 1 μs to 1 s.

[0027] Furthermore, by reading the peak occurrence time of the output voltage curve of the voltage output terminal, the response time of the hydrogen to be measured is obtained, and according to the peak value, the concentration of the hydrogen to be measured is obtained.

[0028] The working principle of the ultrafast hydrogen response sensing structure based on RC differential thin film circuit described in the present invention is:

[0029] The first extraction electrode is connected to a voltage power source to energize the voltage divider / heating thin film resistor, which acts as a heating resistor to generate heat, causing the thin film resistor-type hydrogen sensor unit to reach an operating temperature. When the thin film resistor-type hydrogen sensor unit is exposed to different concentrations of hydrogen, its resistance value changes. Based on the gas adsorption model and the actual response curve shape, the relationship between the resistance response of the thin film resistor-type hydrogen sensor unit and time (i.e., the original resistance response curve) is expressed as an exponential function:

[0030] R(t)=R0+c×(1-e -kt )

[0031] Where R(t) is the real-time resistance value of the thin film resistor type hydrogen sensor unit; R0 is the baseline resistance value when the thin film resistor type hydrogen sensor unit is not responding; c is a constant reflecting the change of hydrogen sensitive thin film resistance with gas concentration; k is a constant reflecting the response speed of hydrogen sensitive thin film resistance.

[0032] The thin film resistor type hydrogen sensor unit and the voltage divider / heating thin film resistor form a voltage divider circuit, which converts the resistance response of the thin film resistor type hydrogen sensor unit into a voltage change, which is input into the RC differential thin film circuit for first-order differentiation. The voltage output end connected to the RC differential thin film circuit outputs the first-order derivative of the original resistance response curve.

[0033] Since the initial slope of the rising edge of the original resistance response curve is different under different hydrogen concentrations, the first-order derivative of the rising edge reflects the hydrogen concentration in the environment. Since the rising rate of the resistance in the original resistance response curve gradually decreases as the device starts to respond, the maximum value of the first-order derivative often appears in a very short time after the device starts to respond, which is much shorter than the time required for the resistance in the original resistance response curve to reach stability. Therefore, the original resistance response curve is differentiated by an RC differential thin film circuit, and the peak value of the first-order derivative output curve is read to quickly detect the hydrogen concentration in the environment.

[0034] Furthermore, the peak moment of the first-order derivative output curve can be altered by adjusting the time constant of the RC differential thin-film circuit. When the time constant of the RC differential thin-film circuit is in the millisecond range, the peak often occurs in the millisecond to hundredths of a millisecond range, significantly less than the sensor's response time constant 1 / k (typically in the second or even hundredths of a second), achieving a response acceleration across orders of magnitude. Furthermore, the peak magnitude is positively correlated with the concentration constant c, which can be used to estimate hydrogen concentration. The time constant is calibrated during device fabrication and testing. In actual use, after reading the first-order derivative output curve of the RC differential thin-film circuit, the response time and magnitude of the ultrafast hydrogen-responsive sensing structure based on the RC differential thin-film circuit are determined by detecting the peak magnitude of the first-order derivative output curve. Furthermore, by detecting the peak magnitude of the output voltage signal and referencing the relationship between the calibrated peak magnitude and the measured hydrogen concentration, the measured hydrogen concentration can be determined.

[0035] Depending on the material and material form, a hydrogen-sensitive thin film resistor whose resistance value increases when responding is called a positive-response hydrogen-sensitive thin film resistor, and a hydrogen-sensitive thin film resistor whose resistance value decreases is called a negative-response hydrogen-sensitive thin film resistor; both positive-response hydrogen-sensitive thin film resistors and negative-response hydrogen-sensitive thin film resistors are suitable for the ultra-fast hydrogen response sensing structure based on RC differential thin film circuit proposed in the present invention, and only show opposite change trends in the direction of the output signal peak.

[0036] After the hydrogen detection is completed, air is introduced into the thin film resistor type hydrogen sensor unit to desorb the hydrogen. The resistance value of the thin film resistor type hydrogen sensor unit is restored, and the voltage at the voltage output end quickly drops back to the baseline value. At this time, the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit returns to its initial state, and the next hydrogen detection can be carried out.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention proposes an ultrafast hydrogen gas response sensing structure based on an RC differential thin-film circuit. This structure converts the resistance change of a thin-film resistive hydrogen gas sensor unit caused by gas adsorption into a voltage change through a voltage divider circuit. The differential characteristics of the RC differential thin-film circuit are then used to perform a first-order differential on the voltage curve output by the thin-film resistive hydrogen gas sensor unit, generating a first-order derivative output curve related to gas concentration. Based on the peak occurrence time and peak value of the first-order derivative output curve, rapid hydrogen gas response and concentration detection are achieved. Compared to traditional resistive gas sensors, which require a stable response to concentration signals, the present invention shortens detection time and significantly improves hydrogen gas response speed.

[0039] 2. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit of the present invention is entirely realized based on thin film materials, which greatly improves the integration of the gas rapid response system. By optimizing the arrangement of each thin film structure, the integration is further improved, and the volume and power consumption of the system are greatly reduced. It can be applied to scenarios with different hydrogen detection requirements and has a wide range of application backgrounds in the fields of new energy gases, hydrogen energy batteries, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 This is a schematic diagram of the principle of an ultrafast hydrogen response sensing structure based on an RC differential thin film circuit proposed in Example 1 of the present invention;

[0042] Figure 2 A schematic structural diagram of an ultrafast hydrogen response sensing structure based on an RC differential thin film circuit provided in Example 1 of the present invention;

[0043] Figure 3 A graph showing the relationship between the peak value of the first-order derivative output curve and the measured hydrogen concentration for the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit provided in Example 1 of the present invention under the condition of a time constant of 1 ms;

[0044] Figure 4 Schematic diagram of the first-order derivative output curve and the original resistance response curve of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit provided in Example 1 of the present invention at different hydrogen concentrations; (a) is a hydrogen concentration of 0.8%; (b) is a hydrogen concentration of 4.0%;

[0045] Figure 5 The first-order derivative output curves of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit provided in Example 1 of the present invention for the same hydrogen concentration at different time constants;

[0046] The descriptions of the symbols in the accompanying drawings are as follows:

[0047] 1. RC differential thin film capacitor, 1-1. First interdigital electrode, 1-2. Dielectric layer, 1-3. Second interdigital electrode; 2. Thin film resistor type hydrogen sensor unit, 3. Voltage divider / heating thin film resistor, 4. RC differential thin film resistor, 5. Substrate, 6. First lead electrode, 7. Second lead electrode, 8. Third lead electrode, 9. Fourth lead electrode. DETAILED DESCRIPTION

[0048] To further understand the present invention, preferred embodiments of the present invention are described below with reference to the following examples. However, it should be understood that these examples are intended only to further illustrate the features and advantages of the present invention and are not intended to limit the scope of the claims. All raw materials used in the present invention are not particularly limited in their sources and may be purchased commercially or prepared according to conventional methods known to those skilled in the art.

[0049] Example 1

[0050] This embodiment provides an ultrafast hydrogen response sensing structure based on RC differential thin film circuit, the principle of which is as follows: Figure 1 As shown, the structure is Figure 2 As shown, it includes a thin film resistance type hydrogen sensor unit 2 located on the surface of a substrate 5, a voltage divider / heating thin film resistor 3, an RC differential thin film circuit and four lead electrodes; the RC differential thin film circuit includes an RC differential thin film capacitor 1 and an RC differential thin film resistor 4.

[0051] The base 5 is composed of a silicon substrate and a silicon oxide insulating layer on its upper surface.

[0052] The RC differential thin film capacitor 1 is of the type of interdigital thin film capacitor, including a first interdigital electrode 1-1, a dielectric layer 1-2 and a second interdigital electrode 1-3. The first interdigital electrode 1-1 and the second interdigital electrode 1-3 are arranged crosswise, and the dielectric layer 1-2 is embedded between the first interdigital electrode 1-1 and the second interdigital electrode 1-3 and completely covers both.

[0053] Among them, the first lead electrode 6 is connected to a 5V DC voltage source and is connected to the end of the first interdigital electrode 1-1 through a voltage divider / heating thin film resistor 3; the second lead electrode 7 is grounded and connected to the end of the first interdigital electrode 1-1 through a thin film resistor type hydrogen sensor unit 2; the third lead electrode 8 is a voltage output end, connected to the end of the second interdigital electrode 1-3; the fourth lead electrode 9 is grounded and connected to the end of the second interdigital electrode 1-3 through an RC differential thin film resistor 4.

[0054] In this embodiment, the thin film resistor type hydrogen sensor unit 2 and the voltage divider / heating thin film resistor 3 are located on one side of the RC differential thin film capacitor 1, and the RC differential thin film resistor 4 is located on the other side of the RC differential thin film capacitor 1, and are compactly arranged.

[0055] The thin film resistor type hydrogen sensor unit 2 has a straight double-bend structure and adopts a positive response hydrogen-sensitive thin film resistor, specifically a palladium-nickel alloy with a thickness of 25nm. The initial resistance value of no response is 950Ω; when the hydrogen concentration is 0.8%, the response resistance is 970Ω; when the hydrogen concentration is 3.2%, the response resistance is 990Ω; when the hydrogen concentration is 4%, the response resistance is 1000Ω.

[0056] The voltage divider / heating thin film resistor 3 is a straight single-bend structure arranged around the thin film resistor type hydrogen sensor unit 2, and is a 30 nm thick gold film with a resistance of 1000Ω.

[0057] The RC differential thin film resistor 4 is a linear serpentine structure and is a 5 nm thick gold film. It has two resistance values, 1 MΩ and 10 MΩ.

[0058] The first interdigital electrode 1 - 1 , the second interdigital electrode 1 - 3 and the four lead electrodes are made of gold thin film; the dielectric layer 1 - 2 is made of silicon oxide with a thickness of 300 nm, and the capacitance value of the RC differential thin film capacitor 1 is 1 nF.

[0059] In this embodiment, all metal films included in the ultrafast hydrogen response sensing structure based on RC differential thin film circuit are prepared by magnetron sputtering process, and the dielectric layers 1-2 are prepared by atomic layer deposition process.

[0060] The voltage divider / heating thin film resistor 3 is energized to generate heat as a heating resistor, so that the thin film resistor type hydrogen sensor unit 2 reaches the operating temperature. The thin film resistor type hydrogen sensor unit 2 is exposed to different concentrations of hydrogen to be measured, and the first-order derivative output curve of the voltage output terminal is obtained.

[0061] According to the above parameters, when the resistance value of the RC differential thin film resistor 4 is 1MΩ and the capacitance value of the RC differential thin film capacitor 1 is 1nF, the time constant of the RC differential thin film circuit is 1ms. At this time, the relationship between the peak value of the first-order derivative output curve of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit and the measured hydrogen concentration is as follows: Figure 3 As shown, when the hydrogen concentration is 0.4%, the peak value of the first-order derivative output curve is 4.67μV; when the hydrogen concentration is 0.8%, the peak value of the first-order derivative output curve is 11.18μV; when the hydrogen concentration is 1.6%, the peak value of the first-order derivative output curve is 21.61μV; when the hydrogen concentration is 3.2%, the peak value of the first-order derivative output curve is 39.98μV; when the hydrogen concentration is 4.0%, the peak value of the first-order derivative output curve is 50.63μV; this shows that the peak value of the first-order derivative output curve output by the RC differential thin film circuit can effectively characterize the concentration of the hydrogen to be measured.

[0062] The schematic diagram of the first-order derivative output curve and the original resistance response curve of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit provided in this embodiment at different hydrogen concentrations is shown in FIG. Figure 4 As shown, when the resistance value of the RC differential thin film resistor 4 is 1MΩ and the capacitance value of the RC differential thin film capacitor 1 is 1nF, the time constant of the RC differential thin film circuit is 1ms, as shown in FIG. Figure 4 As shown in (a), when the hydrogen concentration is 0.8%, the peak of the first-order derivative output curve appears 823ms after the device starts to respond. The response time is 823ms, which is much faster than the 5.23s response time of the thin film resistor type hydrogen sensor unit to reach stability. Figure 4 As shown in (b), at a hydrogen concentration of 4%, the peak of the first-order derivative output curve occurs 614 ms after the device begins responding, resulting in a response time of 614 ms, significantly faster than the 3.14 s required for a thin-film resistor-type hydrogen sensor to reach stable response. This demonstrates that the response time determined based on the peak of the first-order derivative output curve of this embodiment is significantly faster than the time required for a conventional thin-film resistor-type hydrogen sensor to fully respond, enabling rapid detection of hydrogen concentrations.

[0063] In this embodiment, the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit has the following first-order derivative output curves for the same concentration of hydrogen at different time constants: Figure 5As shown, when the hydrogen concentration is uniformly 4%, when the resistance value of the RC differential thin film resistor 4 is 1MΩ and the capacitance value of the RC differential thin film capacitor 1 is 1nF, the time constant of the RC differential thin film circuit is 1ms, the peak of the first-order derivative output curve occurs 528ms after the device starts responding, the response time is 528ms, and the peak value is approximately 42.6μV. When the resistance value of the RC differential thin film resistor 4 is 10MΩ and the capacitance value of the RC differential thin film capacitor 1 is 1nF, the time constant of the RC differential thin film circuit is 10ms, the peak of the first-order derivative output curve occurs 1.14s after the device starts responding, and the response time is 1.14s, which is slightly slower than the case with a time constant of 1ms, but the peak value is approximately 220.5μV, which is much larger than the case with a time constant of 1ms. This shows that this embodiment can adjust the system response speed and response size by adjusting the time constant of the RC differential thin film circuit to adapt to more different application scenarios and needs.

[0064] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. An ultrafast hydrogen response sensing structure based on RC differential thin film circuit, characterized in that: The device comprises a thin film resistor type hydrogen gas sensing unit, a voltage divider / heating thin film resistor, an RC differential thin film circuit and four lead electrodes; the RC differential thin film circuit comprises an RC differential thin film capacitor and an RC differential thin film resistor; the RC differential thin film capacitor comprises a first electrode, a dielectric layer and a second electrode; The first extraction electrode is connected to the first electrode through a voltage divider / heating thin film resistor; the second extraction electrode is connected to the first electrode through a thin film resistor type hydrogen sensor unit; the third extraction electrode is a voltage output terminal, connected to the second electrode; the fourth extraction electrode is connected to the second electrode through an RC differential thin film resistor; The thin film resistor hydrogen sensor unit and the voltage divider / heating thin film resistor form a voltage divider circuit. The voltage divider circuit converts the resistance change of the thin film resistor hydrogen sensor unit caused by gas adsorption into a voltage change. The differential characteristics of the RC differential thin film circuit are then used to perform a first-order differential on the voltage curve output by the thin film resistor hydrogen sensor unit to obtain a first-order derivative output curve related to the gas concentration. Then, based on the peak appearance time and peak value of the first-order derivative output curve, a rapid response to hydrogen and rapid concentration detection are achieved.

2. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The voltage divider / heating thin film resistor is arranged around the thin film resistor type hydrogen sensor unit.

3. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The type of the RC differential film capacitor is an interdigital film capacitor or a planar film capacitor.

4. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The first lead-out electrode is connected to a voltage source, and the second lead-out electrode and the fourth lead-out electrode are grounded.

5. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The resistance ratio of the thin film resistor type hydrogen sensor unit to the pressure divider / heating thin film resistor is in the range of 0.1 to 10.

6. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The thin film resistor type hydrogen sensing unit adopts a positive response hydrogen sensitive thin film resistor or a negative response hydrogen sensitive thin film resistor.

7. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The capacitance value of the RC differential film capacitor ranges from 1 nF to 1 μF.

8. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: The resistance value of the RC differential thin film resistor ranges from 1 KΩ to 1 MΩ.

9. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 1, characterized in that: By adjusting the capacitance value of the RC differential thin film capacitor and the resistance value of the RC differential thin film resistor, the time constant of the RC differential thin film circuit is changed to control the response time and response size of the ultrafast hydrogen response sensing structure based on the RC differential thin film circuit.

10. The ultrafast hydrogen response sensing structure based on RC differential thin film circuit according to claim 9, characterized in that: The time constant ranges from 1 μs to 1 s.

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