Acoustic phonon-carrier coupling dominant intrinsic carrier mobility measurement method

Abstract

The invention discloses an acoustic phonon-carrier coupling dominant intrinsic carrier mobility measurement method, and relates to the technical field of ultrafast optics. The method comprises the following steps: establishing an optical system to realize space coincidence and time coincidence of probe light and pump light, and obtaining a transient reflection spectrum; acquiring a Brillouin oscillation signal based on the transient reflection spectrum to obtain a Brillouin oscillation frequency; calculating to obtain the elastic modulus of the semiconductor material; obtaining the sum of the electron deformation potential and the hole deformation potential by adopting a time domain Brillouin scattering method; obtaining the difference between the electron deformation potential and the hole deformation potential based on the relationship between the semiconductor material optical band gap and the lattice volume, and calculating to obtain the electron deformation potential and the hole deformation potential; and obtaining intrinsic electron mobility and intrinsic hole mobility dominated by the acoustic phonon-carrier coupling effect according to a deformation potential theory. Accurate regulation and control of the defect state density are avoided, and the deformation potential of electrons and holes can be simply and conveniently measured, so that the intrinsic carrier mobility is measured and obtained.

Description

Technical Field

[0001] This invention belongs to the field of ultrafast optics technology, and particularly relates to a method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling. Background Technology

[0002] The electrical properties of semiconductor materials are fundamental to their device applications, with carrier mobility being one of the core parameters determining electrical performance, directly impacting device response speed and efficiency. Scattering mechanisms affecting carrier mobility are mainly divided into two categories: intrinsic scattering and extrinsic scattering. Extrinsic scattering (such as impurity scattering, defect scattering, and surface / interface scattering) limits carrier mobility, thus constraining device performance; while intrinsic scattering (such as electron-phonon scattering) is an inherent characteristic of the material and cannot be avoided. Intrinsic carrier mobility reflects the theoretical upper limit of carrier migration in an ideal semiconductor material when considering only intrinsic scattering mechanisms, and is of great value for predicting device potential and guiding material growth and process optimization. Among many semiconductor materials, carrier-acoustic phonon coupling is a key intrinsic scattering mechanism affecting their transport characteristics. Therefore, elucidating the intrinsic carrier mobility dominated by this mechanism is crucial for understanding carrier transport mechanisms and designing high-performance semiconductor materials.

[0003] Accurately measuring the deformation potentials of electrons and holes, according to deformation potential theory, is crucial for studying the intrinsic carrier mobility dominated by acoustic phonon-carrier coupling in semiconductor materials. Traditional methods primarily rely on first-principles calculations based on density functional theory (DFT), deriving the deformation potential by simulating the shift of the electronic structure (such as the conduction band bottom and valence band top) under lattice strain. However, the results of this method are highly dependent on the selected functional and band correction scheme, introducing uncertainties; furthermore, as a theoretical prediction, its accuracy lacks direct verification with reliable experimental data, making it difficult to serve as a reliable basis for device design and performance evaluation. Currently, methods for experimentally measuring the intrinsic mobility dominated by carrier-acoustic phonon coupling remain relatively limited.

[0004] To address this, the present invention proposes an experimental measurement method for obtaining the intrinsic carrier mobility dominated by carrier-acoustic phonon coupling. This method involves experimentally measuring the deformation potentials of electrons and holes separately, and then calculating the carrier mobilities of electrons and holes under intrinsic acoustic phonon scattering based on deformation potential theory. Summary of the Invention

[0005] The purpose of this invention is to provide an intrinsic carrier mobility measurement method dominated by acoustic phonon-carrier coupling, in order to solve the problems mentioned in the background art, such as the complexity of existing methods for measuring electron and hole deformation potential.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention proposes a method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling, comprising the following steps: S1. Construct an optical system to achieve spatial and temporal overlap of the probe light and pump light, and excite semiconductor materials based on the probe light and pump light in different states to obtain transient reflection spectra; S2. Obtain the Brillouin oscillation signal based on transient reflectance spectrum, and obtain the Brillouin oscillation frequency by fitting the Brillouin oscillation signal; S3. Calculate the elastic modulus of semiconductor materials based on the Brillouin oscillation frequency; S4. The sum of the electron deformation potential and the hole deformation potential is obtained by using the time-domain Brillouin scattering method; S5. Obtain the difference between electronic deformation potential and hole deformation potential based on the relationship between the optical band gap and lattice volume of semiconductor materials; combine the sum of electronic deformation potential and hole deformation potential to calculate electronic deformation potential and hole deformation potential. S6. Based on the calculated elastic modulus, electronic deformation potential, and hole deformation potential of the semiconductor material, the intrinsic electron mobility and intrinsic hole mobility dominated by acoustic phonon-carrier coupling are obtained according to the deformation potential theory.

[0008] Preferably, the optical system in S1 enables the probe light and pump light to coincide both spatially and temporally, as follows: The femtosecond pulse laser output from the femtosecond laser is reflected by mirrors M1 and M2, and then split into pump optical path and probe optical path A by beam splitter S1. For the pump optical path, the pulsed laser, which is modulated by the chopper to half the repetition frequency, enters the NOPA system after being reflected by mirrors M3 and M4 to output a high-energy monochromatic pulsed laser of arbitrary wavelength. After being reflected by mirrors M5 and M6 and focused by lens L1, it finally converges on the semiconductor material sample. For the probe light path A, it is reflected by the mirror M7 into the optical delay line ODL to achieve a relative time delay between the pump light and the probe light. Then, after being focused by the mirror M10 and mirror M11 and the lens L2, it converges on the sapphire crystal to generate supercontinuum white light. The supercontinuum white light is then split into the probe light path B and the reference light path by the beam splitter S2. The reference light path enters the spectrometer after being focused by L4 and reflected by mirror M12. The purpose of the reference light path is to reduce the adverse effects of white light jitter on the experimental results. The probe light path B is reflected by mirrors M13, M14 and M15 and focused by lens L5 onto the sample surface, achieving spatial overlap with the pump light; after being reflected by the sample surface (carrying sample information), the probe light path B is reflected by mirrors M16 and M17 and focused by lens L6 before entering the spectrometer.

[0009] Preferably, the transient reflectance spectrum is obtained in step S1 as follows: First, within the same measurement period, the intensity of the probe light on the semiconductor material is obtained under the presence and absence of pump light, and the amplitude of the transient reflectivity change on the semiconductor material surface is calculated. Then, the relative time delay between the probe light and the pump light is adjusted to obtain the transient reflectance spectrum of the semiconductor material.

[0010] Preferably, the Brillouin oscillation frequency in S2 is calculated as follows: The Brillouin oscillation signal is separated from the transient reflectance spectral data by removing the carrier dynamics background using the adjacent averaging method. The Brillouin oscillation signal is a periodically fluctuating curve segment. The Brillouin oscillation signal is fitted using the sinedamp fitting formula to obtain the Brillouin oscillation frequency.

[0011] Preferably, the elastic modulus of the semiconductor material in S3 is expressed as:

[0012] in, The frequency of the Brillouin oscillation; For semiconductor materials at detection wavelength The refractive index below, The mass density of semiconductor materials. All parameters are known.

[0013] Preferably, step S4 specifically includes the following steps: S4.1 Perform a Fourier transform on the Brillouin oscillation signal to obtain the Brillouin frequency of the semiconductor material, and determine the measured phonon frequency; obtain the calibration factor based on the coherent acoustic phonon spectrum under pump light excitation with different single-photon energies (corresponding to different excitation wavelengths). , Used to calibrate changes in the phonon spectrum caused by variations in penetration depth; S4.2 Obtaining the absorption coefficient of semiconductor materials Used to normalize the effect of carrier concentration on total stress The contribution of the pump light with different single-photon energies is compared to obtain the factor. This is used to represent the amplitude relationship of Brillouin oscillation signals caused by pump light with different single-photon energies; S4.3. Based on the relationship between the total stress caused by pump light with different single-photon energies, combined with the obtained calibration factor... ,factor Calculate the sum of electron deformation potential and hole deformation potential. .

[0014] Furthermore, S4.3 is specifically as follows: The relationship between the total stress induced by pump light of different single-photon energies is expressed as follows:

[0015] Combined total stress The expression yields:

[0016] in, , These represent the total stress caused by pump light with different single-photon energies; Indicates volume modulus. Indicates the coefficient of linear expansion. Indicates heat capacity, and This represents the photon energy of the two pump lights. The optical band gap of semiconductor materials; , , , , and Given the parameters, calculate the sum of the electron deformation potential and the hole deformation potential. .

[0017] Preferably, step S5 is as follows: According to the theory of original deformation potential, electronic deformation potential With the potential of cavitation The definition, combined with the optical bandgap of semiconductor materials ,get:

[0018] Integrating, we get:

[0019] in, It is a constant. The lattice volume; A series of semiconductor materials with similar lattice structures but different lattice parameters were selected, and the optical band gap of each semiconductor material was measured. ,based on and The relationship between them is obtained through linear fitting. ; The difference between electron deformation potential and hole deformation potential Combine the sum of the obtained electron deformation potential and hole deformation potential The electronic deformation potential of the semiconductor material was calculated respectively. With the potential of cavitation .

[0020] Preferably, step S6 is as follows: According to the deformation potential theory, the intrinsic carrier mobility is dominated solely by phonon scattering-carrier coupling. The calculation is as follows:

[0021] in, To reduce Planck's constant, For elementary charge, The elastic modulus of semiconductor materials. The effective mass of charge carriers in a semiconductor material. Boltzmann's constant, For temperature; The carrier deformation potential of semiconductor materials. use or This is used to calculate the intrinsic electron mobility or intrinsic hole mobility of semiconductor materials.

[0022] Compared with the prior art, the beneficial effects of the present invention are: (1) The method of the present invention uses femtosecond laser pulses to excite semiconductor material samples, and the samples will generate coherent acoustic phonons (acoustic stress waves). These stress waves will propagate into the material at a certain speed. By detecting the propagation of these stress waves, the elastic modulus of the material along the direction of stress wave propagation and the sum of electronic deformation potential and hole deformation potential can be obtained. Based on the relationship between the optical band gap and the lattice volume of the semiconductor material, the difference between electronic deformation potential and hole deformation potential is extracted, thereby obtaining the electronic deformation potential and hole deformation potential of the semiconductor material respectively. Finally, based on the deformation potential theory, the intrinsic electronic carrier mobility and intrinsic hole carrier mobility dominated by acoustic phonon-carrier coupling are given respectively.

[0023] (2) Existing methods for measuring intrinsic carrier mobility require precise control of carrier defect types and defect state densities. However, due to the complexity of defects in semiconductor materials, this increases the measurement difficulty. The method proposed in this invention avoids the need for precise control of defect state densities and can relatively easily measure the deformation potentials of electrons and holes separately, thereby measuring the intrinsic carrier mobility of electrons and holes dominated by acoustic phonon-carrier coupling. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the optical system in this invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1: The intrinsic carrier mobility measurement method dominated by acoustic phonon-carrier coupling in this invention mainly includes the following steps: Step (1): Build the optical system.

[0027] like Figure 1 As shown, the optical system description includes a femtosecond laser (Fs-Laser), a mirror, a beam splitter, a lens, an optical delay line (ODL), a NOPA system, and a spectrometer. The mirrors include mirrors M1-M17, the beam splitter includes beam splitters S1 and S2, and the lenses include lenses L1-L6.

[0028] The working process of the optical system is as follows: The femtosecond pulse laser emitted from the femtosecond laser is split into a pump optical path and a probe optical path by a beam splitter S1. The pump optical path is used to excite the semiconductor material to generate acoustic stress waves. The probe optical path is used to detect the Brillouin oscillation signal (i.e., the propagation of the acoustic stress waves) generated by the semiconductor material after optical excitation.

[0029] For the pump optical path, the femtosecond pulsed laser output by the femtosecond laser is first reflected by mirrors M1 and M2, and then modulated by the chopper into a pulsed laser with half the repetition frequency. After being reflected by mirrors M3 and M4, it enters the NOPA system to output a high-energy monochromatic pulsed laser of arbitrary wavelength. Next, after being reflected by mirrors M5 and M6 and focused by lens L1, it finally converges onto the semiconductor material sample.

[0030] For the probe path, the femtosecond pulsed laser output from the femtosecond laser is first reflected by mirror M7 into the optical delay line (ODL) to achieve a relative time delay between the pump and probe beams. Then, it is focused by mirrors M10 and M11 and lens L2 onto the sapphire crystal to generate supercontinuum white light. This supercontinuum white light is then split into a probe path and a reference path by beam splitter S2. The reference beam is focused by L4 and reflected by mirror M12 before entering the spectrometer. The purpose of the reference path is to reduce the adverse effects of white light jitter on the experimental results. The probe beam is reflected by mirrors M13, M14, and M15 and focused by lens L5 onto the sample surface, achieving spatial overlap with the pump beam. After being reflected by the sample surface (carrying sample information), the probe beam is reflected by mirrors M16 and M17 and focused by lens L6 before entering the spectrometer.

[0031] The change in transient reflectivity of the semiconductor material surface in this invention can be expressed as:

[0032] in, This indicates the presence of pump photoexcitation materials. Detecting wavelengths at all times Intensity of reflected light; Indicates when there is no pump light Detecting wavelengths at all times Intensity of reflected light.

[0033] Therefore, after pump light excitation time, The transient reflectivity change of semiconductor materials at the detection wavelength can be represented by equation (1).

[0034] This invention utilizes an optical system to achieve spatial and temporal overlap between the probe light and the pump light. Specifically, within the same measurement period, the intensity of the probe light is obtained for the material with and without the pump light. Substituting these two intensity values ​​into formula (1), the amplitude of the transient reflectance change on the material surface at time 0 can be calculated. Furthermore, based on the optical delay line (ODL), the relative time delay between the probe light and the pump light is continuously changed to test the transient reflectance spectrum of the semiconductor material. A method for measuring the elastic modulus of a semiconductor material, with publication number 202510364761.3, discloses the acquisition of transient reflectance spectra.

[0035] Step (2): Analyze the generation of coherent acoustic phonons and Brillouin oscillation signals to obtain Brillouin oscillation signals.

[0036] This invention uses transient reflectance spectroscopy based on the time-domain Brillouin scattering principle to measure the intrinsic carrier mobility of semiconductor materials. Time-domain Brillouin scattering probes the intrinsic charge transport characteristics of semiconductor materials by detecting the propagation behavior of coherent acoustic phonons (CAPs). In this invention, CAPs are generated primarily through two methods: thermoelastic stress and deformation potential stress.

[0037] When a beam of light with energy far exceeding the band gap of a semiconductor material excites it, some of the energy is absorbed for electron transitions, while the excess energy is transferred to the crystal lattice, generating thermal expansion stress through thermal expansion. It can be represented as:

[0038] in The bulk modulus of a semiconductor material. The coefficient of linear expansion is 1 / 3. Carrier concentration, The energy for pump light, For the band gap of the material, It is the heat capacity.

[0039] When photoexcites electrons from the valence band to the conduction band, the binding energy between atoms changes, and this change induces the generation of deformation potential stress. It can be represented as:

[0040] in Carrier concentration, and These correspond to the electron deformation potential and hole deformation potential of semiconductor materials, respectively.

[0041] So the total stress It can be represented as:

[0042] During transient reflection testing, the surface of the semiconductor material reflects a probe beam. The CAP (Capacitor Interface) forms a movable optical interface and also reflects a probe beam that penetrates into the material. These two probe beams satisfy the interference condition and interfere at the detector. Simultaneously, the CAP propagates into the material at a certain speed, causing the phase difference between the two probe beams to change linearly over time, thus inducing oscillations in the transient reflection spectrum (i.e., Brillouin oscillations).

[0043] This invention separates the oscillation signal by removing the carrier dynamics background in the transient reflection spectrum, and then obtains the frequency and amplitude of the Brillouin oscillation signal by fitting the coherent acoustic phonon signal.

[0044] Step (3): Extraction of the elastic modulus of semiconductor materials.

[0045] In this invention, the elastic modulus As a prerequisite parameter for calculating the intrinsic carrier mobility of semiconductor materials, it is related to the Brillouin oscillation frequency. The following relationship exists:

[0046] in The frequency of the Brillouin oscillation is... Semiconductor materials in detection wavelength The refractive index below, The speed of sound (the speed at which CAP propagates). This represents the mass density of the semiconductor material.

[0047] According to formulas (5) and (6), the elastic modulus of semiconductor materials It can be represented as , It is known that and This can be obtained by consulting relevant literature. It can be obtained by fitting a Brillouin oscillation signal. The Brillouin oscillation signal in this invention can be fitted using the following formula:

[0048] in The initial amplitude of the Brillouin oscillation is given by the total stress. Related, This represents the initial phase of the Brillouin oscillation, i.e., the time point at which the CAP event occurs. For the decay lifetime of Brillouin oscillations, The period of the Brillouin oscillation is equal to the frequency of the Brillouin oscillation. The reciprocal of.

[0049] Step (4): Use time-domain Brillouin scattering to extract the sum of carrier deformation potentials of semiconductor materials.

[0050] As can be seen from formula (4), when the carrier concentration is kept constant, changing only the pump photon energy will result in a deformation potential stress. Nothing changes, but thermal expansion stress This changes with the pump photon energy. Based on this, the carrier deformation potential of semiconductor materials can be extracted by changing the pump photon energy.

[0051] (4-1) Obtaining the calibration factor Used to calibrate changes in the phonon spectrum caused by variations in penetration depth: It is worth noting that time-domain Brillouin scattering (TDS) measures phonons at a specific Brillouin frequency, and the measured signal amplitude only represents a portion of the total acoustic strain. Therefore, a Fourier transform must be performed on the measured Brillouin oscillation signal to obtain the Brillouin frequency of the semiconductor material.

[0052] Pump light with different single-photon energies has different penetration depths, and variations in penetration depth cause changes in the coherent acoustic phonon spectrum. Therefore, it is necessary to calibrate for the changes caused by differences in penetration depth. The coherent acoustic phonon spectrum of a semiconductor material excited by pump light with different single-photon energies can be reconstructed using the following formula:

[0053] in , , The depth of the pump light penetration into the semiconductor material. For the speed of sound, The extinction coefficient at a certain pump wavelength, Let be the reflection coefficient of the semiconductor material, expressed as: , Let be the refractive index at a given pump wavelength. Assume... The values ​​are similar, and the coherent acoustic phonon spectrum (amplitude) under pump light excitation with different single-photon energies can be reproduced. (Relationship with frequency). Based on the Brillouin frequency obtained through Fourier transform, the calibration factor can be obtained from the coherent acoustic phonon spectrum excited by pump light with different single-photon energies. To calibrate the changes in the phonon spectrum caused by variations in penetration depth.

[0054] (4-2) Obtaining the absorption coefficient Used to normalize the effect of carrier concentration on total stress Contributions: Semiconductor materials absorb pump light of different single-photon energies differently. This absorption difference leads to inconsistent carrier concentrations within the semiconductor material even under the same excitation photon number density. The amplitude of the Brillouin oscillation signal is related to the total stress. Related, and total stress It is also related to carrier concentration. Therefore, the Brillouin oscillation signal must be divided by the absorption coefficient of the semiconductor material at the pump wavelength to normalize the carrier concentration versus total stress. The contribution of semiconductor materials. This can be expressed as follows:

[0055] The reflectance coefficient of the semiconductor material is shown in (4-1) for specific calculation. Let be the transmission coefficient of the semiconductor material. The absorption coefficient of the semiconductor material can be calculated using formula (9). Used to normalize the effect of carrier concentration on total stress . contributions.

[0056] (4-3) Obtaining Factors This is used to represent the amplitude relationship of Brillouin oscillation signals induced by pump light with different single-photon energies: Normalized carrier concentration versus total stress After considering the contribution, the differences in the amplitude of Brillouin oscillation signals between pump lights with different single-photon energies are compared to establish the relationship between the amplitudes of Brillouin oscillation signals induced by pump lights with different single-photon energies. This invention uses a factor... This relationship is expressed as follows: the normalized carrier concentration affects the total stress. The contribution is specifically to divide the acquired Brillouin oscillation signal by the absorption coefficient. This causes the amplitude of the Brillouin oscillation signal to change accordingly. By comparing the differences in the amplitude of the Brillouin oscillation signal between pump lights with different single-photon energies, the factor is obtained. .

[0057] Therefore, the relationship between the total stress caused by pump light with different single-photon energies can be expressed as follows (taking 360 nm and 480 nm pump light as examples):

[0058] By combining equations (4), we can obtain:

[0059] For equation (11), the bulk modulus Coefficient of linear expansion and heat capacity All of these can be obtained by consulting the literature; pump light photon energy and Given parameters, The band gap of semiconductor materials can be obtained through photoluminescence experiments or by consulting literature. (Factor) and This can be obtained using the method described above. Therefore, the sum of the carrier deformation potentials of the semiconductor material can be calculated. .

[0060] Step (5): Extract the difference in carrier deformation potential and the decoupled carrier deformation potential of the semiconductor material; In this invention, on the one hand, the sum of electron and hole deformation potentials is extracted using time-domain Brillouin scattering in step (4). On the other hand, in step (5), the difference between electron and hole deformation potentials is extracted based on the relationship between the optical band gap and lattice volume of the semiconductor material. Thus, electron and hole deformation potentials can be extracted separately. Finally, based on deformation potential theory, the intrinsic electron carrier mobility and intrinsic hole carrier mobility dominated by acoustic phonon-carrier coupling are given respectively. and The process is the essential difference between this invention and the prior art.

[0061] According to the original deformation potential theory, the deformation potential of charge carriers (electrons and holes) can be defined as:

[0062] in, This represents the energy at the conduction band bottom of a semiconductor material. The energy at the valence band peak of semiconductor materials. It refers to the lattice volume. This is due to the band gap in semiconductor materials. ,So:

[0063] further:

[0064] Integrating equation (14), we get:

[0065] in It is a constant.

[0066] During the experiment, a series of semiconductor materials with similar lattice structures but different lattice parameters were selected, and the optical band gap of each material was measured. Based on formula (15) and The relationship between them is obtained through linear fitting. Then, combining the sum of the carrier deformation potentials obtained above... Then the electronic deformation potential of the semiconductor material can be calculated separately. With the potential of cavitation .

[0067] Step (6): Calculation of intrinsic carrier mobility of semiconductor material.

[0068] According to the deformation potential theory, the intrinsic carrier mobility dominated solely by the intrinsic scattering mechanism (carrier-phonon scattering) is calculated as follows:

[0069] in To reduce Planck's constant, For elementary charge, The elastic modulus of semiconductor materials. The effective mass of charge carriers (electrons or holes) in a semiconductor material (which can be obtained by consulting the literature). Boltzmann's constant, For temperature, This refers to the deformation potential of charge carriers (electrons or holes) in a semiconductor material. The obtained... and ( and Substituting into formula (16), the intrinsic electron mobility and intrinsic hole mobility of the semiconductor material can be obtained.

[0070] The above description is only for the purpose of helping to understand the method and core essence of the present invention, but the scope of protection of the present invention is not limited thereto. For those skilled in the art, any equivalent substitutions or modifications made within the technical scope disclosed in the present invention, based on the technical solution and inventive concept, should be covered within the scope of protection of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling, characterized in that, Includes the following steps: S1. Construct an optical system to achieve spatial and temporal overlap of the probe light and pump light, and excite semiconductor materials based on the probe light and pump light in different states to obtain transient reflection spectra; S2. Obtain the Brillouin oscillation signal based on transient reflectance spectrum, and obtain the Brillouin oscillation frequency by fitting the Brillouin oscillation signal; S3. Calculate the elastic modulus of semiconductor materials based on the Brillouin oscillation frequency; S4. The sum of the electron deformation potential and the hole deformation potential is obtained by using the time-domain Brillouin scattering method; S5. Obtain the difference between electron deformation potential and hole deformation potential based on the relationship between optical band gap and lattice volume of semiconductor materials; The electron deformation potential and the hole deformation potential are calculated by combining the sum of the electron deformation potential and the hole deformation potential. S6. Based on the calculated elastic modulus, electronic deformation potential, and hole deformation potential of the semiconductor material, the intrinsic electron mobility and intrinsic hole mobility dominated by acoustic phonon-carrier coupling are obtained according to the deformation potential theory.

2. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 1, characterized in that, The transient reflectance spectrum is obtained in S1 as follows: First, within the same measurement period, the intensity of the probe light on the semiconductor material is obtained under the presence and absence of pump light, and the amplitude of the transient reflectivity change on the semiconductor material surface is calculated. Then, the relative time delay between the probe light and the pump light is adjusted to obtain the transient reflectance spectrum of the semiconductor material.

3. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 1, characterized in that, The Brillouin oscillation frequency in S2 is calculated as follows: First, the carrier dynamics background is removed from the transient reflectance spectral data to separate the Brillouin oscillation signal; then, the Brillouin oscillation signal is fitted using a fitting formula to obtain the Brillouin oscillation frequency.

4. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 3, characterized in that, The elastic modulus of the semiconductor material in S3 is expressed as: in, The frequency of the Brillouin oscillation; For semiconductor materials at detection wavelength The refractive index below, The mass density of semiconductor materials. All parameters are known.

5. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 1, characterized in that, S4 specifically includes the following steps: S4.1 Perform a Fourier transform on the Brillouin oscillation signal to obtain the Brillouin frequency of the semiconductor material, and determine the measured phonon frequency; obtain the calibration factor based on the coherent acoustic phonon spectrum under pump light excitation with different single-photon energies. , Used to calibrate changes in the phonon spectrum caused by variations in penetration depth; S4.2 Obtaining the absorption coefficient of semiconductor materials Used to normalize the effect of carrier concentration on total stress The contribution of the pump light with different single-photon energies is compared to obtain the factor. This is used to represent the amplitude relationship of Brillouin oscillation signals caused by pump light with different single-photon energies; S4.

3. Based on the relationship between the total stress caused by pump light with different single-photon energies, combined with the obtained calibration factor... ,factor Calculate the sum of electron deformation potential and hole deformation potential. .

6. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 5, characterized in that, S4.3 is as follows: The relationship between the total stress induced by pump light of different single-photon energies is expressed as follows: Combined total stress The expression yields: in, , These represent the total stress caused by two pump lights with different single-photon energies; Indicates volume modulus. Indicates the coefficient of linear expansion. Indicates heat capacity, and This represents the photon energy of the two pump lights. The optical band gap of semiconductor materials; , , , , and Given the parameters, calculate the sum of the electron deformation potential and the hole deformation potential. .

7. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 1, 5, or 6, characterized in that, S5 is specifically as follows: According to the theory of original deformation potential, electronic deformation potential With the potential of cavitation The definition, combined with the optical bandgap of semiconductor materials ,get: Integrating, we get: in, It is a constant. The lattice volume; A series of semiconductor materials with similar lattice structures but different lattice parameters were selected, and the optical band gap of each semiconductor material was measured. ,based on and The relationship between them is obtained through linear fitting. ; The difference between electron deformation potential and hole deformation potential Combine the sum of the obtained electron deformation potential and hole deformation potential The electronic deformation potential of the semiconductor material was calculated respectively. With the potential of cavitation .

8. The method for measuring intrinsic carrier mobility dominated by acoustic phonon-carrier coupling according to claim 7, characterized in that, S6 is specifically as follows: According to the deformation potential theory, the intrinsic carrier mobility is dominated solely by phonon scattering-carrier coupling. The calculation is as follows: in, To reduce Planck's constant, For elementary charge, The elastic modulus of semiconductor materials. The effective mass of charge carriers in a semiconductor material. Boltzmann's constant, For temperature; The carrier deformation potential of semiconductor materials. use or This is used to calculate the intrinsic electron mobility or intrinsic hole mobility of semiconductor materials.

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