In-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano material

Abstract

The invention relates to the field of data measurement, and discloses a thermoelectric, rectification and Hall effect in-situ integrated measurement method for a micro-nano material, and the method is applied to a thermoelectric, rectification and Hall effect in-situ integrated measurement device, and comprises the steps: placing a to-be-measured sample made of the micro-nano material on a first surface of a substrate in a suspended manner, a to-be-tested sample is in contact with part of the microelectrodes, the snakelike microelectrodes are electrified and heated, and thermal performance parameters of the to-be-tested sample are measured; connecting a constant current source with the microelectrode, and measuring the electrical property parameters of the to-be-measured sample; applying a magnetic field, and measuring and calculating Hall thermal effect parameters of the to-be-measured sample and Hall effect parameters of the to-be-measured sample. The thermal conductivity, the conductivity, the Seebeck coefficient, the thermoelectric figure of merit, the thermal / electric rectification coefficient, the Hall thermal conductivity, the carrier concentration, the mobility and other parameters of the to-be-measured sample are directly measured in situ on the micro-nano material sample, the accuracy of the measurement result is improved, and a foundation is laid for research of a thermal electromagnetic coupling transport mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of data measurement, and in particular to an in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials. Background Art

[0002] The thermal Hall effect refers to the phenomenon that when an external magnetic field perpendicular to the temperature gradient is applied to a material with a temperature gradient, hot carriers are deflected, resulting in a heat flow perpendicular to the temperature gradient in the material, and a lateral temperature difference is generated. In the actual measurement process of the thermal Hall effect, the experimental measurement of the thermal Hall effect is difficult because the effective signal of the thermal Hall effect is relatively small compared to the background noise signal. At present, the measurement of the thermal Hall effect is mainly focused on macroscopic materials, whose size is at the mm level.

[0003] In the prior art, there is still a gap in the in-situ integrated measurement of the thermoelectric properties, rectification properties and Hall properties of micro-nano materials, making it difficult to carry out research on the thermo-electromagnetic coupling transport mechanism. At present, the measurement of different properties of micro-nano materials in experiments mainly adopts the method of multiple sample preparation and separate measurement. Using different measurement methods to measure different physical properties of the same sample to be tested will cause the transmission of errors, further increase the measurement error, and lead to low measurement accuracy of sample properties. Due to the limitations of micro-nano technology, the existing preparation process cannot guarantee the consistency of the prepared samples, and measurement errors may occur when measuring different properties of the sample through multiple sample preparations. Summary of the invention

[0004] In view of this, the present invention provides an in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials to solve the problems that it is difficult to measure the thermal Hall effect of micro-nano materials and there is a gap in the in-situ integrated measurement of thermoelectric properties, rectification properties and Hall properties, making it difficult to carry out research on thermal electromagnetic coupling transport mechanisms.

[0005] In a first aspect, the present invention provides an in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials, which is applied to an in-situ integrated measurement device of thermoelectricity, rectification and Hall effect, wherein the in-situ integrated measurement device of thermoelectricity, rectification and Hall effect comprises a substrate and a plurality of serpentine microelectrodes and a plurality of microelectrodes arranged on a first surface of the substrate. The method performs in-situ integrated measurement of thermoelectricity, rectification and Hall effect on the same sample to be measured, and the method comprises:

[0006] A sample to be tested made of micro-nano material is suspended on the first surface of the substrate, the sample to be tested is in contact with a part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested through the microelectrodes to measure the thermoelectric performance parameters of the sample to be tested;

[0007] Connect the constant current source and the microelectrode, and conduct through the sample to be tested to measure the electrical rectification performance parameters of the sample to be tested, and energize and heat the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested;

[0008] The serpentine microelectrode is electrically heated and a magnetic field perpendicular to the direction of heat flow is applied, so that the sample to be tested produces a thermal Hall effect, a lateral temperature difference is generated, and the Hall thermal effect parameters of the sample to be tested are calculated;

[0009] A current is applied to the sample to be tested through a constant current source and a magnetic field perpendicular to the current direction is applied, so that the sample to be tested generates a Hall effect, the Hall voltage of the sample to be tested is measured, and the Hall effect parameters of the sample to be tested are calculated. The Hall thermal effect parameters and the Hall effect parameters constitute the Hall effect measurement results.

[0010] The present invention places the sample to be tested in mid-air on the surface of a substrate to form a suspended state, and heats it with electricity through a serpentine microelectrode, and measures the thermoelectric performance parameters and thermal rectification performance parameters of the sample to be tested. After the sample to be tested generates thermal Hall effect and Hall effect, the Hall thermal effect parameters and Hall effect parameters of the sample to be tested are measured, and the relevant parameters are characterized in situ without the need for multiple sample preparations, so as to achieve in-situ integrated precise measurement of multiple parameters on the same sample, and there is no measurement dependency between the parameters, laying a foundation for the study of thermal electromagnetic coupling transport mechanism.

[0011] In an optional embodiment, the thermoelectric performance parameters include thermal conductivity, electrical conductivity, Seebeck coefficient and thermoelectric figure of merit, and the step of measuring the thermoelectric performance parameters of the sample to be tested includes:

[0012] Measuring the heat received by the serpentine microelectrode heat sink end, and calculating the thermal conductivity of the sample to be tested according to the heat received by the serpentine microelectrode heat sink end;

[0013] Calculate the conductivity of the sample to be tested;

[0014] Measuring the Seebeck voltage and the serpentine microelectrode temperature difference of the sample to be tested, and calculating the Seebeck coefficient of the sample to be tested based on the Seebeck voltage and the serpentine microelectrode temperature difference;

[0015] The absolute temperature of the sample to be tested is measured, and the thermoelectric figure of merit of the sample to be tested is calculated according to the absolute temperature, Seebeck coefficient, electrical conductivity and thermal conductivity.

[0016] The present invention reflects the thermoelectric energy parameter performance of the sample to be tested by measuring the thermal conductivity, electrical conductivity, Seebeck coefficient and thermoelectric figure of merit of the sample to be tested respectively.

[0017] In an optional implementation, the calculating the conductivity of the sample to be tested includes:

[0018] Measure the cross-sectional area of the sample to be measured and the spacing of the serpentine microelectrodes by scanning electron microscopy, measure the voltage of the microelectrodes with a high-impedance voltmeter, and record the current of the constant current source;

[0019] Calculate the conductivity of the sample to be measured according to the voltage of the serpentine microelectrodes, the current of the constant current source, the cross-sectional area of the sample to be measured, and the spacing of the serpentine microelectrodes.

[0020] The present invention calculates the conductivity of the sample to be measured according to the parameters of the microelectrodes, the current parameters of the connected constant current source, and the parameters of the sample to be measured, so as to reflect the conductance performance of the sample to be measured.

[0021] In an optional embodiment, connecting the constant current source and the microelectrodes and conducting through the sample to be measured to measure the electrical rectification performance parameters of the sample to be measured, and energizing and heating the serpentine microelectrodes to measure the thermal rectification performance parameters of the sample to be measured, including:

[0022] According to the conductivity calculation method, change the current input direction and measure and calculate the electrical rectification coefficient of the sample to be measured;

[0023] Change the directions of the heating end and the heat sink end of the serpentine microelectrodes and measure the thermal rectification coefficient of the sample to be measured.

[0024] The present invention simplifies the parameters required for calculation and facilitates measurement by changing the current input direction and measuring the electrical rectification coefficients of the sample to be measured in different directions.

[0025] In an optional embodiment, the Hall thermal conductance parameter is the Hall thermal conductivity, and calculating the Hall thermal effect parameters of the sample to be measured includes:

[0026] Calculate the Hall thermal conductivity of the sample to be measured according to the transverse temperature difference and the thermal conductivity.

[0027] The present invention calculates the Hall thermal conductivity of the sample to be measured by using the transverse temperature difference and the thermal conductivity to reflect the Hall thermal effect of the sample to be measured.

[0028] In an optional embodiment, the thermoelectric, rectification and Hall effect in-situ integrated measurement device further includes a plurality of electrodes arranged on the first surface of the substrate, the Hall effect parameters include Hall voltage, carrier mobility and carrier concentration, and measuring the Hall effect parameters of the sample to be measured includes:

[0029] Energize the electrodes in contact with the sample to be measured, apply a magnetic field perpendicular to the current direction to the sample to be measured, and measure the Hall voltage of the sample to be measured;

[0030] Measure the charge of the carriers in the sample to be measured, and calculate the carrier concentration of the sample to be measured based on the charge of the carriers and the Hall coefficient;

[0031] The carrier mobility of the sample to be tested is calculated based on the conductivity of the sample to be tested and the charge quantity of the carrier.

[0032] The present invention measures the Hall voltage and the charge of the carriers to calculate the carrier concentration of the sample to be tested, thereby calculating the carrier mobility.

[0033] In an optional embodiment, the method further includes:

[0034] The Hall coefficient of the sample to be tested is calculated based on the Hall voltage of the sample to be tested.

[0035] The present invention calculates the Hall coefficient of the sample to be tested according to the Hall voltage of the sample to be tested, so as to reflect the Hall parameter of the sample to be tested.

[0036] In a second aspect, the present invention provides an in-situ integrated measurement device for thermoelectricity, rectification and Hall effect of micro-nano materials, the device comprising:

[0037] The first measurement module is used to place the sample to be tested made of micro-nano material in the air on the first surface of the substrate, the sample to be tested is in contact with part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested to measure the thermoelectric performance parameters of the sample to be tested;

[0038] The second measurement module is used to connect the constant current source and the microelectrode, and conduct through the sample to be tested to measure the electrical rectification performance parameters of the sample to be tested, and to energize and heat the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested;

[0039] The thermal Hall effect generation module is used to electrically heat the serpentine microelectrode and apply a magnetic field perpendicular to the direction of the heat flow, so that the sample to be tested generates a thermal Hall effect, generates a lateral temperature difference, and calculates the Hall thermal effect parameters of the sample to be tested;

[0040] The third measurement module applies current to the sample to be tested through a constant current source and applies a magnetic field in a direction perpendicular to the current, so that the sample to be tested generates a Hall effect, measures the Hall voltage of the sample to be tested, and calculates the Hall effect parameters of the sample to be tested. The Hall thermal effect parameters and the Hall effect parameters constitute the Hall effect measurement results.

[0041] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials of the above-mentioned first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0042] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a schematic diagram of an in-situ integrated measurement device for thermoelectric, rectification and Hall effect according to an embodiment of the present invention;

[0045] Figure 2 It is a schematic flow chart of an in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials according to an embodiment of the present invention;

[0046] Figure 3 : is a structural block diagram of an in-situ integrated measurement device for thermoelectricity, rectification and Hall effect of micro-nano materials according to an embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention;

[0048] Description of reference numerals:

[0049] 100. Sample to be tested; 11. Detection area; 12. Silicon nitride; 1. First microelectrode; 2. Second microelectrode; 3. Third microelectrode; 4. Fourth microelectrode; 5. Fifth microelectrode; 6. Sixth microelectrode; 7. Seventh microelectrode; 8. Eighth microelectrode. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0051] In the actual measurement process of the thermal Hall effect, the effective signal of the thermal Hall effect is relatively small compared to the background noise signal, so the experimental measurement of the thermal Hall effect is difficult. At present, the measurement of the thermal Hall effect is mainly focused on macroscopic materials, whose size is at the mm level.

[0052] In the relevant technology, there is still a gap in the in-situ integrated measurement of thermoelectric properties, rectification properties and Hall properties of micro-nano materials. At present, the measurement of different properties of micro-nano materials in experiments mainly adopts the method of multiple sample preparation and separate measurement. Using different measurement methods to measure different physical properties of the same sample to be tested will cause the transmission of errors, further increase the measurement error, and lead to low measurement accuracy of sample properties. Due to the limitations of micro-nano technology, the existing preparation process cannot guarantee the consistency of the prepared samples, and measurement errors may occur when measuring different properties of the sample through multiple sample preparations.

[0053] According to an embodiment of the present invention, an embodiment of an in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0054] In this embodiment, a method for in-situ integrated measurement of thermoelectricity, rectification and Hall effect of micro-nano materials is provided, which is applied to an in-situ integrated measurement device for thermoelectricity, rectification and Hall effect, such as Figure 1 As shown, Figure 1 1 is a schematic diagram of an in-situ integrated measurement of thermoelectricity, rectification and Hall effect, wherein the in-situ integrated measurement of thermoelectricity, rectification and Hall effect comprises a substrate and a plurality of serpentine microelectrodes and a plurality of microelectrodes arranged on a first surface of the substrate. A sample 100 to be tested is placed in a detection area 11. Figure 1 The silicon nitride 12 in the microelectrode 1 forms a uniform temperature layer, which effectively controls the temperature and reduces the heat loss. Among them, the second microelectrode 2 and the sixth microelectrode 6 are serpentine microelectrodes, and the fourth microelectrode 4 and the eighth microelectrode 8 can be serpentine, needle-shaped or linear microelectrodes. The first microelectrode 1, the third microelectrode 3, the fifth microelectrode 5 and the seventh microelectrode 7 are all formed into a linear structure.

[0055] To achieve in-situ integrated measurement of ten related parameters of thermoelectric properties, rectification effect and Hall effect of thermoelectric materials, the in-situ integrated measurement of multiple data can be achieved by simply placing the sample 100 to be tested in the detection area 11 of the detector, which is convenient for analyzing the thermal-electric-magnetic coupling transport mechanism.

[0056] Figure 2 is a flow chart of an in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0057] In step S201, a sample to be tested made of micro-nano material is suspended on the first surface of the substrate, the sample to be tested is in contact with part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested through the microelectrodes to measure the thermoelectric performance parameters of the sample to be tested.

[0058] In the embodiment of the present invention, the thermoelectric performance parameters include thermal conductivity, electrical conductivity, Seebeck coefficient and thermoelectric figure of merit. Figure 1 On the first surface of the substrate shown, the sample to be tested is directly connected to the first microelectrode 1, the third microelectrode 3, the fifth microelectrode 5, and the seventh microelectrode 7, while the sample to be tested is not directly connected to the second microelectrode 2, the fourth microelectrode 4, the sixth microelectrode 6, and the eighth microelectrode 8, but is directly in contact with the temperature-averaging layer formed by silicon nitride. By energizing and heating the first microelectrode 1, the sixth microelectrode 6 acts as a thermal sensor to receive the heat conducted from the sample to be tested, thereby measuring the thermal conductivity parameters of the sample to be tested.

[0059] Step S202, connecting the constant current source and the microelectrode, and conducting through the sample to be tested, measuring the electrical rectification performance parameters of the sample to be tested, and electrically heating the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested.

[0060] In the embodiment of the present invention, the thermal rectification performance parameters include the thermal rectification coefficient, and the electrical rectification performance parameters of the sample to be tested are measured by connecting a constant current source and a microelectrode, conducting the sample to be tested, and changing the direction of the current. The serpentine microelectrode is electrically heated, and the directions of the heating end and the heat sink end are changed to measure the thermal rectification performance parameters of the sample to be tested.

[0061] Step S203, the serpentine microelectrode is electrically heated and a magnetic field perpendicular to the heat flow direction is applied, so that the sample to be tested generates a thermal Hall effect, generates a lateral temperature difference, and calculates the Hall thermal effect parameters of the sample to be tested.

[0062] In the embodiment of the present invention, the Hall thermal effect parameters include the Hall thermal conductivity of the sample to be tested. The second microelectrode 2 and the sixth microelectrode 6 serve as the heating end and the heat sink end, respectively, so that a heat flow is generated in the sample to be tested. At this time, due to the action of the magnetic field, the sample to be tested generates a thermal Hall effect and produces a lateral temperature difference, so as to calculate the Hall thermal effect parameters of the sample to be tested.

[0063] Step S204 , applying a current to the sample to be tested and applying a magnetic field perpendicular to the direction of the sample to be tested through a constant current source, so that the sample to be tested generates a Hall effect, the Hall voltage of the sample to be tested is measured, and the Hall effect parameters of the sample to be tested are calculated.

[0064] The Hall thermal effect parameters of the sample to be tested and the Hall effect parameters of the sample to be tested constitute the Hall effect measurement result.

[0065] In the embodiment of the present invention, a current is applied to the sample to be tested by a constant current source and a magnetic field perpendicular to the direction of the sample to be tested is applied, so that the sample to be tested generates a Hall effect. The Hall voltage of the sample to be tested can be measured by the first microelectrode 1, the third microelectrode 3 or the fifth microelectrode 5, the seventh microelectrode 7 to calculate the Hall effect parameters of the sample to be tested.

[0066] The in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials provided in this embodiment is to place the sample to be tested in mid-air on the surface of a substrate to form a suspended state, and to heat it through a serpentine microelectrode, to measure the thermoelectric performance parameters and thermal rectification performance parameters of the sample to be tested, and after the sample to be tested generates thermal Hall effect and Hall effect, to measure the Hall thermal effect parameters and Hall effect parameters of the sample to be tested, and to characterize the relevant parameters in-situ, without the need for multiple sample preparations, so as to achieve in-situ integrated precise measurement of multiple parameters on the same sample, and there is no measurement dependency between the parameters, which lays a foundation for the study of thermal electromagnetic coupling transport mechanism.

[0067] Specifically, in one embodiment, the thermoelectric performance parameters of the sample to be tested are measured in the above step S201, which specifically includes the following steps:

[0068] Step S2011, measuring the amount of heat received by the serpentine microelectrode heat sink end, and calculating the thermal conductivity of the sample to be tested according to the amount of heat received by the serpentine microelectrode heat sink end of the sample to be tested.

[0069] Step S2012, calculating the conductivity of the sample to be tested.

[0070] Step S2013, measuring the Seebeck voltage and the serpentine microelectrode temperature difference of the sample to be tested, and calculating the Seebeck coefficient of the sample to be tested based on the Seebeck voltage and the serpentine microelectrode temperature difference of the sample to be tested.

[0071] Step S2014, measuring the absolute temperature of the sample to be tested, and calculating the thermoelectric figure of merit of the sample to be tested according to the absolute temperature, Seebeck coefficient, electrical conductivity and thermal conductivity of the sample to be tested.

[0072] In the embodiment of the present invention, the first microelectrode 1 is powered on for heating, and the sixth microelectrode 6 is used as a thermal sensor to receive the heat conducted from the sample to be tested to calculate the thermal conductivity of the sample to be tested. The temperature-averaging layer makes the temperatures of the three electrodes on the left and right sides quickly stabilize and consistent, so that the second microelectrode 2 and the sixth microelectrode 6 can be used as temperature sensors to calculate the temperature difference. The microelectrode temperature is calculated by the formula of the change of electrode resistance with temperature. The thermal conductivity of the sample to be tested is obtained by the following formula:

[0073]

[0074] Where λ is the thermal conductivity of the sample to be tested, Q is the amount of heat flowing through the sample to be tested, and ΔT 1 is the temperature difference (ΔT) between the second microelectrode 2 and the sixth microelectrode 6 1 =T 1 -T 6 ), R 2 , R′ 2 and R 6 , R′ 6 They are the initial resistance of the second microelectrode 2 and the sixth microelectrode 6 and the resistance when the resistance changes due to heat as a temperature sensor resistance, and α is the resistance temperature coefficient of the microelectrode.

[0075] While measuring thermal conductivity, since a temperature difference is formed between the first microelectrode 1 and the seventh microelectrode 7, the Seebeck voltage can be obtained at both ends of the temperature difference according to the Seebeck effect of the thermoelectric material. Therefore, a high-resolution voltmeter is connected to the first microelectrode 1 and the seventh microelectrode 7 to measure the Seebeck voltage. Due to the existence of the uniform temperature layer, the temperature difference between the first microelectrode 1 and the seventh microelectrode 7 is also the temperature difference between the second microelectrode 2 and the sixth microelectrode 6. The Seebeck coefficient of the sample to be tested can be obtained by the following formula:

[0076]

[0077] Where S is the Seebeck coefficient of the sample to be tested, U is the Seebeck voltage of the sample to be tested, ΔT 2 is the temperature difference (ΔT) between the first microelectrode 1 and the seventh microelectrode 7 2 =T 1 -T 7 ), the Seebeck coefficient of the sample to be tested can be calculated based on the results of thermal conductivity measurement.

[0078] According to the definition of thermoelectric figure of merit ZT, the calculation formula of ZT can be obtained:

[0079]

[0080] Where ZT is the thermoelectric figure of merit, and T is the absolute temperature of the sample to be tested.

[0081] The thermal conductivity, electrical conductivity, Seebeck coefficient and thermoelectric figure of merit of the sample to be tested are measured respectively to reflect the thermoelectric energy parameter performance of the sample to be tested.

[0082] Specifically, in one embodiment, the above step S2012 calculates the conductivity of the sample to be tested, and specifically includes the following steps:

[0083] Step S20121, measure the cross-sectional area of ​​the sample to be tested and the spacing between the serpentine microelectrodes by means of a scanning electron microscope, measure the voltage of the microelectrodes by means of a high impedance voltmeter, and record the current of the constant current source.

[0084] Step S20122, calculating the conductivity of the sample to be tested according to the voltage of the serpentine microelectrode of the sample to be tested, the current of the constant current source, the cross-sectional area of ​​the sample to be tested and the spacing between the serpentine microelectrodes.

[0085] In the embodiment of the present invention, when measuring the conductivity, a constant current source is connected to the first microelectrode 1 and the seventh microelectrode 7 through the sample to be tested, and then a high impedance voltmeter (V) is used to connect the third microelectrode 3 and the fifth microelectrode 5 to measure the voltage. The conductivity is calculated by the following formula:

[0086]

[0087] Where, σ is the conductivity of the sample to be tested, ρ is the resistivity of the sample to be tested, R is the resistance, A is the cross-sectional area of ​​the sample to be tested, and L is the 1 is the distance between the third microelectrode 3 and the fifth microelectrode 5, I is the current of the constant current source, V 1 is the voltage obtained by the high impedance voltmeter.

[0088] The conductivity of the sample to be tested is calculated according to the parameters of the microelectrode, the current parameters of the constant current source connected, and the parameters of the sample to be tested, so as to reflect the conductivity performance of the sample to be tested.

[0089] Specifically, in one embodiment, in the above step S202, the constant current source and the microelectrode are connected, and the sample to be tested is turned on to measure the electrical rectification performance parameters of the sample to be tested, and the serpentine microelectrode is electrically heated to measure the thermal rectification performance parameters of the sample to be tested, which specifically includes the following steps:

[0090] Step S2021, according to the conductivity calculation method, change the current input direction, and measure and calculate the electrical rectification coefficient of the sample to be tested.

[0091] Step S2022, changing the directions of the heating end and the heat sink end of the serpentine microelectrode, and measuring the thermal rectification coefficient of the sample to be tested.

[0092] In the embodiment of the present invention, the direction of the output current of the constant current source is changed to measure the conductivity σ′ of the sample to be tested in different directions, thereby calculating the electrical rectification coefficient δ of the sample to be tested:

[0093]

[0094] By changing the direction of the heating end and the heat sink end of the microelectrode, the thermal conductivity λ and λ′ in different directions can be measured, and the thermal rectification coefficient of the sample to be tested can be calculated:

[0095]

[0096] Where η is the thermal rectification coefficient of the sample to be tested, and λ′ is the thermal conductivity in the opposite direction after changing the heating end and the heat sink end of the microelectrode.

[0097] By changing the current input direction, the electrical rectification coefficient of the sample to be tested in different directions is measured, which simplifies the parameters required for calculation and facilitates measurement.

[0098] Specifically, in one embodiment, the calculation of the Hall thermal effect parameters of the sample to be tested in the above step S203 specifically includes the following steps:

[0099] Step S2031, calculating the Hall thermal conductivity of the sample to be tested according to the transverse temperature difference and thermal conductivity of the sample to be tested.

[0100] In the embodiment of the present invention, when measuring the thermal Hall effect, a magnetic field perpendicular to the sample to be tested is applied, and the second microelectrode 2 and the sixth microelectrode 6 are respectively used as the heating end and the heated end to generate heat flow in the sample to be tested. At this time, due to the effect of the magnetic field, a thermal Hall effect is generated in the sample to be tested, resulting in a lateral temperature difference. The temperature of the lateral ends of the sample to be tested is measured by the fourth microelectrode 4 and the eighth microelectrode 8. The lateral temperature difference (ΔT 3 =T 4 -T 8 ) can be calculated by the following formula:

[0101]

[0102] Based on the measured lateral temperature difference, the Hall thermal conductivity λ″ of the sample to be tested can be calculated. The calculation formula is as follows:

[0103]

[0104] Specifically, in one embodiment, the calculation of the Hall effect parameters of the sample to be tested in the above step S204 specifically includes the following steps:

[0105] Step S2041: Apply a magnetic field perpendicular to the direction of the current to the sample to be tested, energize the electrodes in contact with the sample to be tested, and measure the Hall voltage of the sample to be tested.

[0106] Step S2042 , measuring the charge amount of carriers in the sample to be tested, and calculating the carrier concentration of the sample to be tested based on the charge amount of carriers in the sample to be tested and the Hall coefficient.

[0107] Step S2043 , calculating the carrier mobility of the sample to be tested based on the conductivity of the sample to be tested and the charge quantity of the carriers of the sample to be tested.

[0108] In an embodiment of the present invention, the carrier concentration of the sample to be tested is further calculated according to the following formula:

[0109]

[0110] Wherein, e is the charge of the carriers in the sample to be tested.

[0111] The carrier concentration of the sample to be tested is calculated by measuring the Hall voltage and the charge of the carriers, thereby calculating the carrier mobility.

[0112] Step S405 , calculating the carrier mobility of the sample to be tested based on the conductivity of the sample to be tested and the charge amount of the carriers.

[0113] In an embodiment of the present invention, the carrier mobility of the sample to be tested is further calculated according to the following formula:

[0114]

[0115] The carrier concentration of the sample to be tested is calculated by measuring the Hall voltage and the charge of the carriers, thereby calculating the carrier mobility.

[0116] Specifically, in one embodiment, the in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials provided by the embodiment of the present invention further includes the following steps:

[0117] Step S205 , calculating the Hall coefficient of the sample to be tested based on the Hall voltage of the sample to be tested.

[0118] In the embodiment of the present invention, when measuring the Hall effect parameters of the sample to be tested, a current I is passed through the first microelectrode 1 and the seventh microelectrode 7 in the sample to be tested under the condition of applying a magnetic field perpendicular to the sample to be tested. S The Hall voltage V of the sample to be tested can be measured by the first microelectrode 1, the third microelectrode 3 or the fifth microelectrode 5, the seventh microelectrode 7. H , the Hall coefficient R of the sample to be tested is calculated by the following formula H :

[0119]

[0120] Where d is the thickness of the sample to be tested, and B is the applied magnetic field strength.

[0121] The Hall coefficient of the sample to be tested is calculated according to the Hall voltage of the sample to be tested to reflect the Hall parameter of the sample to be tested.

[0122] In addition, the in-situ integrated measurement of thermoelectricity, rectification and Hall effect of micro-nano materials provided in this embodiment measures ten physical parameters at one time, and the relevant parameters are characterized in-situ without multiple sample preparation, thereby ensuring the reliability and accuracy of the measurement results. The measurement results are more accurate, and there is no measurement dependency between the parameters, so as to analyze the thermal-electric-magnetic coupling transport mechanism, and provide a reliable characterization means for studying the thermoelectric-rectification-Hall coupling mechanism. There is no measurement dependency between the parameters, and they do not affect each other, thereby improving the measurement accuracy.

[0123] This method not only breaks the limitation that existing technologies can only be used to measure the thermal Hall effect of macroscopic materials, but can also measure the thermoelectric figure of merit of irregular geometric materials, and has a wider range of sample applications. It not only realizes the in-situ integrated characterization of the thermoelectric properties, rectification effect and Hall effect of micro-nano materials, but also eliminates the need to use different measurement methods, samples and equipment for multiple measurements. It also avoids measurement errors or even erroneous results caused by multiple sample preparations, multiple measurements and calculations, ensuring correct measurement results and high-precision measurements.

[0124] In this embodiment, a Hall effect measuring device of micro-nano materials is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0125] This embodiment provides an in-situ integrated measurement device for thermoelectricity, rectification and Hall effect of micro-nano materials, such as Figure 3 As shown, including:

[0126] The first measurement module 301 is used to place the sample to be tested made of micro-nano materials in the air on the first surface of the substrate, the sample to be tested is in contact with part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested to measure the thermoelectric performance parameters of the sample to be tested.

[0127] The second measurement module 302 is used to connect the constant current source and the microelectrode, and conduct the sample to be tested to measure the electrical rectification performance parameters of the sample to be tested, and to energize and heat the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested.

[0128] The thermal Hall effect generation module 303 is used to electrically heat the serpentine microelectrode and apply a magnetic field perpendicular to the heat flow direction, so that the sample to be tested generates a thermal Hall effect, generates a lateral temperature difference, and calculates the Hall thermal effect parameters of the sample to be tested.

[0129] The third measurement module 304 applies current to the sample to be tested through a constant current source and applies a magnetic field in a direction perpendicular to the current, so that the sample to be tested generates a Hall effect, measures the Hall voltage of the sample to be tested, and calculates the Hall effect parameters of the sample to be tested. The Hall thermal effect parameters and the Hall effect parameters constitute the Hall effect measurement results.

[0130] In some optional implementations, the first measurement module 301 includes:

[0131] A first calculation unit is used to measure the heat received by the serpentine microelectrode heat sink end, and calculate the thermal conductivity of the sample to be tested according to the heat received by the serpentine microelectrode heat sink end;

[0132] A second calculation unit, used for calculating the conductivity of the sample to be tested;

[0133] a third calculation unit, used for measuring the Seebeck voltage and the serpentine microelectrode temperature difference of the sample to be tested, and calculating the Seebeck coefficient of the sample to be tested based on the Seebeck voltage and the serpentine microelectrode temperature difference;

[0134] The fourth calculation unit is used to measure the absolute temperature of the sample to be tested, and calculate the thermoelectric figure of merit of the sample to be tested according to the absolute temperature, Seebeck coefficient, electrical conductivity and thermal conductivity.

[0135] In some optional implementations, the second computing unit includes:

[0136] A measuring subunit is used to measure the cross-sectional area of ​​the sample to be tested and the spacing of the serpentine microelectrodes through a scanning electron microscope, measure the voltage of the microelectrodes through a high impedance voltmeter, and record the current of the constant current source;

[0137] The calculation subunit is used to calculate the conductivity of the sample to be tested according to the voltage of the serpentine microelectrode, the current of the constant current source, the cross-sectional area of ​​the sample to be tested and the spacing between the serpentine microelectrodes.

[0138] In some optional implementations, the second measurement module 302 includes:

[0139] The first measuring unit is used to change the current input direction according to the conductivity calculation method to measure and calculate the electrical rectification coefficient of the sample to be tested.

[0140] The second measuring unit is used for changing the directions of the heating end and the heat sink end of the serpentine microelectrode and measuring the thermal rectification coefficient of the sample to be measured.

[0141] In some optional embodiments, the thermal Hall effect generation module 303 includes:

[0142] The fifth calculation unit is used to calculate the Hall thermal conductivity of the sample to be tested according to the transverse temperature difference and the thermal conductivity.

[0143] In some optional implementations, the third measurement module 304 includes:

[0144] The third measuring unit is used to apply a magnetic field perpendicular to the current direction to the sample to be tested, energize the electrodes in contact with the sample to be tested, and measure the Hall voltage of the sample to be tested.

[0145] The sixth calculation unit is used to measure the charge amount of the carriers in the sample to be tested, and calculate the carrier concentration of the sample to be tested based on the charge amount of the carriers and the Hall coefficient.

[0146] The seventh calculation unit is used to calculate the carrier mobility of the sample to be tested based on the conductivity of the sample to be tested and the charge amount of the carriers.

[0147] In some optional embodiments, the device further comprises:

[0148] The calculation module is used to calculate the Hall coefficient of the sample to be tested based on the Hall voltage of the sample to be tested.

[0149] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0150] The Hall effect measurement device of micro-nano materials in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0151] The embodiment of the present invention also provides a computer device having the above Figure 3 The Hall effect measurement device of micro-nano materials is shown.

[0152] See also Figure 4 , Figure 4 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 4As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 4 A processor 10 is taken as an example.

[0153] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0154] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0155] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0156] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0157] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 4 The example of connecting through bus is taken in the following.

[0158] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen. The output device 40 can include a display device, etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0159] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0160] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials. It is characterized in that The invention is applied to an in-situ integrated measurement device for thermoelectricity, rectification and Hall effect, wherein the in-situ integrated measurement device for thermoelectricity, rectification and Hall effect comprises a substrate and a plurality of serpentine microelectrodes and a plurality of microelectrodes arranged on a first surface of the substrate. The method performs in-situ integrated measurement of thermoelectricity, rectification and Hall effect on the same sample to be measured, and the method comprises: A sample to be tested made of micro-nano material is suspended on the first surface of the substrate, the sample to be tested is in contact with a part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested through the microelectrodes to measure the thermoelectric performance parameters of the sample to be tested; Connect the constant current source and the microelectrode, and conduct through the sample to be tested to measure the electrical rectification performance parameters of the sample to be tested, and energize and heat the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested; The serpentine microelectrode is electrically heated and a magnetic field perpendicular to the direction of heat flow is applied, so that the sample to be tested produces a thermal Hall effect, a lateral temperature difference is generated, and the Hall thermal effect parameters of the sample to be tested are calculated; A current is applied to the sample to be tested through a constant current source and a magnetic field perpendicular to the current direction is applied, so that the sample to be tested generates a Hall effect, the Hall voltage of the sample to be tested is measured, and the Hall effect parameters of the sample to be tested are calculated. The Hall thermal effect parameters and the Hall effect parameters constitute the Hall effect measurement results.

2. The method according to claim 1, It is characterized in that The thermoelectric performance parameters include thermal conductivity, electrical conductivity, Seebeck coefficient and thermoelectric figure of merit. The thermoelectric performance parameters of the sample to be tested are measured, including: Measuring the heat received by the serpentine microelectrode heat sink end, and calculating the thermal conductivity of the sample to be tested according to the heat received by the serpentine microelectrode heat sink end; Calculate the conductivity of the sample to be tested; Measuring the Seebeck voltage and the serpentine microelectrode temperature difference of the sample to be tested, and calculating the Seebeck coefficient of the sample to be tested based on the Seebeck voltage and the serpentine microelectrode temperature difference; The absolute temperature of the sample to be tested is measured, and the thermoelectric figure of merit of the sample to be tested is calculated according to the absolute temperature, Seebeck coefficient, electrical conductivity and thermal conductivity.

3. The method according to claim 2, It is characterized in that The step of calculating the conductivity of the sample to be tested comprises: The cross-sectional area of ​​the sample to be tested and the spacing between the serpentine microelectrodes were measured by a scanning electron microscope, the voltage of the microelectrodes was measured by a high impedance voltmeter, and the current of the constant current source was recorded; The conductivity of the sample to be tested is calculated according to the voltage of the serpentine microelectrode, the current of the constant current source, the cross-sectional area of ​​the sample to be tested and the spacing between the serpentine microelectrodes.

4. The method according to claim 1, It is characterized in that The constant current source is connected to the microelectrode, and the sample to be tested is turned on to measure the electrical rectification performance parameters of the sample to be tested, and the serpentine microelectrode is electrically heated to measure the thermal rectification performance parameters of the sample to be tested, including: According to the conductivity calculation method, change the current input direction and measure and calculate the electrical rectification coefficient of the sample to be tested; The directions of the heating end and the heat sink end of the serpentine microelectrode are changed, and the thermal rectification coefficient of the sample to be tested is measured.

5. The method according to claim 2, It is characterized in that The Hall thermal conductivity parameter is the Hall thermal conductivity, and the calculation of the Hall thermal effect parameter of the sample to be tested includes: The Hall thermal conductivity of the sample to be tested is calculated according to the transverse temperature difference and the thermal conductivity.

6. The method according to claim 2, It is characterized in that The thermoelectric, rectification and Hall effect in-situ integrated measurement device further includes a plurality of electrodes arranged on the first surface of the substrate. The Hall effect parameters include Hall voltage, carrier mobility and carrier concentration. The calculation of the Hall effect parameters of the sample to be measured includes: Apply a magnetic field perpendicular to the direction of the current to the sample to be tested, energize the electrodes in contact with the sample to be tested, and measure the Hall voltage of the sample to be tested; Measuring the charge of carriers in the sample to be tested, and calculating the carrier concentration of the sample to be tested based on the charge of the carriers and the Hall coefficient; The carrier mobility of the sample to be tested is calculated based on the conductivity of the sample to be tested and the charge quantity of the carrier.

7. The method according to claim 6, It is characterized in that The method further comprises: The Hall coefficient of the sample to be tested is calculated based on the Hall voltage of the sample to be tested.

8. An in-situ integrated measurement device for thermoelectricity, rectification and Hall effect of micro-nano materials, It is characterized in that The device comprises: The first measurement module is used to place the sample to be tested made of micro-nano material in the air on the first surface of the substrate, the sample to be tested is in contact with part of the microelectrodes, the serpentine microelectrodes are electrically heated, and a constant current source is connected to the sample to be tested to measure the thermoelectric performance parameters of the sample to be tested; The second measurement module is used to connect the constant current source and the microelectrode, and conduct through the sample to be tested to measure the electrical rectification performance parameters of the sample to be tested, and to energize and heat the serpentine microelectrode to measure the thermal rectification performance parameters of the sample to be tested; The thermal Hall effect generation module is used to electrically heat the serpentine microelectrode and apply a magnetic field perpendicular to the direction of the heat flow, so that the sample to be tested generates a thermal Hall effect, generates a lateral temperature difference, and calculates the Hall thermal effect parameters of the sample to be tested; The third measurement module applies current to the sample to be tested through a constant current source and applies a magnetic field in a direction perpendicular to the current, so that the sample to be tested generates a Hall effect, measures the Hall voltage of the sample to be tested, and calculates the Hall effect parameters of the sample to be tested. The Hall thermal effect parameters and the Hall effect parameters constitute the Hall effect measurement results.

9. A computer device, It is characterized in that include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the in-situ integrated measurement method of thermoelectricity, rectification and Hall effect of micro-nano materials according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the in-situ integrated measurement method for thermoelectricity, rectification and Hall effect of micro-nano materials according to any one of claims 1 to 7.

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