Method for measuring carrier dynamics of halogenated non-fullerene organic photovoltaic system

Abstract

The invention discloses a method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system, which is a method for measuring carrier recombination dynamics of the halogenated non-fullerene organic photovoltaic system by combining an ultrafast transient absorption spectrum technology. Measurement and data analysis and processing of non-radiative complex dynamics of different halogenated organic systems can be realized, and flexibility and accuracy of measurement are further improved by utilizing a pumping-detection technology. Besides, the transient absorption spectrum system can be adjusted through a mechanical delay line, the required time domain resolution can be achieved by combining with a delay signal generator, dynamic information on the picosecond time scale and the nanosecond time scale is provided, and the research on the organic photoelectric conversion process is facilitated.

Description

Technical Field

[0001] The present application relates to the field of organic optoelectronic technology, and in particular to a method for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system. Background Art

[0002] In recent years, polymer-based organic solar cells have attracted widespread attention. Compared with traditional inorganic semiconductors, such organic polymer solar cells have the advantages of simple preparation process, flexibility, low cost, and rich application scenarios. At present, in the application of organic solar cells, non-fullerene acceptor materials have become a research hotspot. These materials are gradually replacing traditional fullerene acceptors with their excellent performance and ease of regulation.

[0003] At present, from the perspective of charge loss and energy loss, for non-fullerene acceptor photovoltaic devices, some charge transfer and separation processes involved in organic photoelectric conversion usually occur on a picosecond or even shorter time scale, while existing technologies cannot achieve the measurement of carrier dynamics in halogenated non-fullerene organic photovoltaic systems. Summary of the invention

[0004] The present application aims to at least solve the technical problems existing in the prior art. To this end, the first aspect of the present application proposes a method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system, characterized in that the method comprises:

[0005] Obtain multiple groups of comparative test samples;

[0006] For each group of comparison test samples, the pre-built ultrafast transient absorption spectroscopy system is controlled to measure the spectral dynamic changes of the comparison test samples under preset excitation conditions to obtain two-dimensional spectral data;

[0007] After data processing and comparative analysis of each group of two-dimensional spectral data, the comparison results of carrier dynamics of halogenated non-fullerene organic photovoltaic system are generated.

[0008] In a possible implementation, the ultrafast transient absorption spectroscopy system includes a pump optical path module, a detection optical path module, and a data acquisition module, and controls the pre-built ultrafast transient absorption spectroscopy system to measure and compare the spectral dynamics changes of the test sample under preset excitation conditions to obtain two-dimensional spectral data, including:

[0009] Controlling the pump optical path module to generate pump light, so as to excite the test sample through pump light contrast;

[0010] Controlling the detection light path module to generate detection light, so as to measure and compare the spectral dynamics changes of the test sample under the preset excitation conditions through the detection light, and obtain two-dimensional spectral data; wherein the preset excitation conditions are determined according to the pump light wavelength, excitation position and excitation intensity of the pump light;

[0011] The data acquisition module is controlled to acquire two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device for processing.

[0012] In a possible implementation, the method further includes:

[0013] Controlling the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light; wherein the central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz;

[0014] Controlling a beam splitter disposed at an output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam; wherein the light intensity of the first light beam is greater than the light intensity of the second light beam;

[0015] Controlling the first light beam to generate pump light through a first nonlinear optical crystal in a pump optical path module; the first nonlinear optical crystal comprises a barium metaborate crystal;

[0016] The second light beam is controlled to converge onto the second nonlinear optical crystal through the flip mirror and the lens in the detection optical path module, and the detection light is generated in the second nonlinear optical crystal through multiple nonlinear processes; wherein the detection light includes signal light and reference light, the reference light is not affected by the pump light, and the second nonlinear optical crystal includes yttrium aluminum garnet crystal, potassium titanyl phosphate crystal and sapphire crystal.

[0017] In a possible implementation, the spectral dynamics changes of the comparison test sample under the preset excitation conditions are measured by detecting light to obtain two-dimensional spectral data, including:

[0018] For the pump light under each preset excitation condition, the detection light and the pump light are controlled to hit the comparison test sample, and the signal light in the detection light is controlled to overlap with the pump light on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample to obtain the detection light after passing through the comparison test sample;

[0019] The detection light after passing through the comparison test sample is controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0020] In a possible implementation, after data processing and comparison analysis of each set of two-dimensional spectral data, a comparison result of carrier dynamics of a halogenated non-fullerene organic photovoltaic system is generated, including:

[0021] For each group of two-dimensional spectral data, an average value corresponding to a preset number of data points is obtained, and the average value is used as an unexcited signal; wherein the unexcited signal includes an ambient light signal and an interference signal;

[0022] After removing the unexcited signal from the two-dimensional spectrum data, transient absorption measurement is performed, and the differential change rate of the transmittance of the comparison test sample to the detection light under pump light excitation and without pump light excitation is calculated, and the differential change rate of the transmittance is used as the transient absorption signal;

[0023] Comparing the transient absorption signal with the preset steady-state absorption signal in a preset band and with a preset time delay to determine whether an intermediate state absorption signal is obtained;

[0024] Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate state absorption signal, the proportion of non-radiative recombination of charges in different systems is compared, and the comparison results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system are obtained.

[0025] In a possible implementation, the transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

[0026] In a possible implementation, the transient absorption measurement also includes nanosecond-resolved transient absorption measurement, which generates a first signal and a second signal through a delayed signal generator, and uses the delayed signal between the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

[0027] In a second aspect, the present application provides a device for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system, the device comprising an ultrafast transient absorption spectroscopy system and a computer device, wherein the ultrafast transient absorption spectroscopy system and the computer device are communicatively connected, wherein:

[0028] The ultrafast transient absorption spectroscopy system is used to obtain multiple groups of comparison test samples; for each group of comparison test samples, the spectral dynamics changes of the comparison test samples under preset excitation conditions are measured to obtain two-dimensional spectral data, and the two-dimensional spectral data is sent to the computer device;

[0029] The computer equipment is used to obtain each group of two-dimensional spectral data, and after data processing and comparative analysis of each group of two-dimensional spectral data, generate a comparison result of carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

[0030] In a possible implementation, the ultrafast transient absorption spectroscopy system includes a pump optical path module, a detection optical path module and a data acquisition module, and the ultrafast transient absorption spectroscopy system is further used for:

[0031] Controlling the pump optical path module to generate pump light, so as to excite the test sample through pump light contrast;

[0032] Controlling the detection light path module to generate detection light, so as to measure and compare the spectral dynamics changes of the test sample under the preset excitation conditions through the detection light, and obtain two-dimensional spectral data; wherein the preset excitation conditions are determined according to the pump light wavelength, excitation position and excitation intensity of the pump light;

[0033] The data acquisition module is controlled to acquire two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device for processing.

[0034] In a possible embodiment, the above-mentioned device for measuring carrier dynamics of halogenated non-fullerene organic photovoltaic system is also used for:

[0035] Controlling the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light; wherein the central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz;

[0036] Controlling a beam splitter disposed at an output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam; wherein the light intensity of the first light beam is greater than the light intensity of the second light beam;

[0037] Controlling the first light beam to generate pump light through a first nonlinear optical crystal in a pump optical path module; the first nonlinear optical crystal comprises a barium metaborate crystal;

[0038] The second light beam is controlled to converge onto the second nonlinear optical crystal through the flip mirror and the lens in the detection optical path module, and the detection light is generated in the second nonlinear optical crystal through multiple nonlinear processes; wherein the detection light includes signal light and reference light, the reference light is not affected by the pump light, and the second nonlinear optical crystal includes yttrium aluminum garnet crystal, potassium titanyl phosphate crystal and sapphire crystal.

[0039] In a possible implementation, the ultrafast transient absorption spectroscopy system is further used for:

[0040] For the pump light under each preset excitation condition, the detection light and the pump light are controlled to hit the comparison test sample, and the signal light in the detection light is controlled to overlap with the pump light on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample to obtain the detection light after passing through the comparison test sample;

[0041] The detection light after passing through the comparison test sample is controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0042] In a possible implementation manner, the computer device is specifically used for:

[0043] For each group of two-dimensional spectral data, an average value corresponding to a preset number of data points is obtained, and the average value is used as an unexcited signal; wherein the unexcited signal includes an ambient light signal and an interference signal;

[0044] After removing the unexcited signal from the two-dimensional spectrum data, transient absorption measurement is performed, and the differential change rate of the transmittance of the comparison test sample to the detection light under pump light excitation and without pump light excitation is calculated, and the differential change rate of the transmittance is used as the transient absorption signal;

[0045] Comparing the transient absorption signal with the preset steady-state absorption signal in a preset band and with a preset time delay to determine whether an intermediate state absorption signal is obtained;

[0046] Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate state absorption signal, the proportion of non-radiative recombination of charges in different systems is compared, and the comparison results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system are obtained.

[0047] In a possible implementation, the transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

[0048] In a possible implementation, the transient absorption measurement also includes nanosecond-resolved transient absorption measurement, which generates a first signal and a second signal through a delayed signal generator, and uses the delayed signal between the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

[0049] The third aspect of the present application proposes an electronic device, which includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system as described in the first aspect.

[0050] In a fourth aspect, the present application proposes a computer-readable storage medium, wherein the storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system as described in the first aspect.

[0051] The embodiments of the present application have the following beneficial effects:

[0052] The method for measuring the carrier dynamics of the halogenated non-fullerene organic photovoltaic system provided in the embodiment of the present application includes: obtaining multiple groups of comparison test samples, for each group of comparison test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamics changes of the comparison test samples under preset excitation conditions, obtaining two-dimensional spectral data, and performing data processing and comparison analysis on each group of two-dimensional spectral data to generate a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system. This scheme combines the ultrafast transient absorption spectroscopy technology to measure the carrier recombination dynamics of the halogenated non-fullerene organic photovoltaic system, which can realize the measurement and data analysis of the non-radiative recombination dynamics of different halogenated organic systems, and further improves the flexibility and accuracy of the measurement by using the pump-probe technology; in addition, the transient absorption spectroscopy system can be adjusted by a mechanical delay line, combined with a delay signal generator to achieve the required time domain resolution, and provide dynamic information on the picosecond and nanosecond time scales, which is convenient for studying the process of organic photoelectric conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A block diagram of a computer device provided in an embodiment of the present application;

[0054] Figure 2 A flow chart of the steps of a method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system provided in an embodiment of the present application;

[0055] Figure 3 A flowchart of the steps for obtaining two-dimensional spectral data provided in an embodiment of the present application;

[0056] Figure 4 A flowchart of the steps of generating pump light and detection light provided in an embodiment of the present application;

[0057] Figure 5 Another flow chart of steps for obtaining two-dimensional spectral data provided in an embodiment of the present application;

[0058] Figure 6 A flowchart of the steps for generating a comparison result provided in an embodiment of the present application;

[0059] Figure 7 A schematic diagram of the structure of an ultrafast transient absorption spectroscopy system provided in an embodiment of the present application;

[0060] Figure 8 A schematic diagram showing the comparison of transient spectra of a Y5 triplet sensitized sample obtained by sensitization and a comparison test sample at 1500ps provided in an embodiment of the present application;

[0061] Fig. 9 A schematic diagram of transient absorption dynamics of a power-dependent PBDB-T:Y5 comparison test sample provided in an embodiment of the present application;

[0062] Fig.10 A schematic diagram of transient absorption spectra of three groups of PBDB-T:Y5, PM6:Y6 and PM6:Y7 comparison test samples with a delay of 1ns provided in an embodiment of the present application;

[0063] Fig.11 A schematic diagram of picosecond time-resolved kinetic curves of three groups of comparative test samples at 1450nm provided in an embodiment of the present application;

[0064] Fig.12 A schematic diagram of nanosecond time-resolved kinetic curves of three groups of comparative test samples at 940nm and 1150nm provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0066] In recent years, polymer-based organic solar cells (OSCs) have attracted widespread attention. Compared with traditional inorganic semiconductors, such organic polymer solar cells have the advantages of simple preparation process, flexibility, low cost, and rich application scenarios. The application of non-fullerene acceptors has further improved the efficiency of organic solar cells. The highest efficiency reported so far has exceeded 20%. Since the synthesis and application of non-fullerene acceptors, the power conversion efficiency of OSCs has been continuously improved. These acceptors have shown first-class photovoltaic performance. The conversion efficiency of non-fullerene acceptors (NFAs) organic solar cells has been greatly improved, thanks to the advantages of NFAs such as wider absorption spectrum coverage, long excitation diffusion length, and reduced non-radiative recombination losses. Organic small molecule acceptors represented by Y6 have further improved the efficiency of OSCs. Organic small molecule acceptors also include Y5 and Y7.

[0067] The end groups of organic small molecule receptors will affect the optoelectronic performance of organic solar cell devices. At present, researchers have modified the structure of non-fullerene small molecule receptors using different regulatory methods (such as end group engineering, side chain engineering, skeleton engineering, etc.), and designed and synthesized a series of highly efficient NFAs. On the one hand, the push-pull electron effect within the organic receptor molecule is affected by the electron-withdrawing ability of the end group; on the other hand, the stacking between organic receptor molecules mainly depends on the interaction between the end group and the molecule. Therefore, end group modification is one of the effective ways to regulate the spectral absorption, energy level and crystallization behavior of receptor molecules. By introducing electron-withdrawing halogen atoms such as F atoms and Cl atoms into the end group, the optical band gap can usually be narrowed, the energy level can be lowered, the interaction between molecules can be increased, the charge transfer can be improved, and it is beneficial to obtain higher short-circuit current and fill factor. In addition, F atoms have high electronegativity and can form and non-covalent interactions in molecules to promote charge transfer.

[0068] Exploring the dynamics of photovoltaic materials in excited states, especially the generation and recombination mechanism of photogenerated charges, is of great significance for understanding the working mechanism of photovoltaic devices and breaking through the barriers that limit their performance improvement. Ultrafast spectroscopy technology can monitor the non-equilibrium dynamic changes of materials in excited states under light excitation on a full time scale, and is a key means to study the excited state dynamics of organic photovoltaic materials. Compared with the fullerene receptor system, the NFAs system exhibits unique excited state characteristics. In the photoelectric conversion channel of the polymer / NFA system, the electron transfer channel and the hole transfer channel proceed simultaneously, allowing the NFAs system to be realized under a very small interface potential difference.

[0069] From the perspective of charge loss and energy loss, there are multiple different energy loss mechanisms in non-fullerene acceptor photovoltaic devices. The generation and recombination of triplet states are two key dynamic processes that affect the effective charge splitting. The generation of triplet excitons (T1) usually occurs through the intersystem crossing (ISC) process of singlet excitons, which is a transition process from singlet state (S1) to triplet state (T1). Triplet recombination involves the interaction between triplet excitons and charge carriers (such as electrons or holes), resulting in non-radiative loss of exciton energy. Existing technologies cannot achieve the measurement of carrier dynamics in halogenated non-fullerene organic photovoltaic systems.

[0070] Based on this, the present application proposes a method for measuring the carrier dynamics of a halogenated non-fullerene organic photovoltaic system, including: obtaining multiple groups of comparison test samples, for each group of comparison test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamics changes of the comparison test samples under preset excitation conditions, obtaining two-dimensional spectral data, and performing data processing and comparison analysis on each group of two-dimensional spectral data to generate a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system. This scheme combines the ultrafast transient absorption spectroscopy technology to measure the carrier recombination dynamics of halogenated non-fullerene organic photovoltaic systems, and can achieve the measurement and data analysis of non-radiative recombination dynamics of different halogenated organic systems, and further improve the flexibility and accuracy of the measurement by using pump-probe technology; in addition, the transient absorption spectroscopy system can be adjusted through a mechanical delay line, combined with a delay signal generator to achieve the required time domain resolution, and provide dynamic information on the picosecond and nanosecond time scales, which is convenient for studying the process of organic photoelectric conversion.

[0071] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0072] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, steps, calculations or other actions "based on" or "according to" one or more of the conditions or values ​​may be based on additional conditions or values ​​beyond the described values ​​in practice.

[0073] The method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system provided in the present application can be applied to a computer device (electronic device), and the computer device can be a server or a terminal, wherein the server can be a single server or a server cluster composed of multiple servers. The embodiments of the present application do not specifically limit this, and the terminal can be but is not limited to various personal computers, laptops, smart phones, tablet computers and portable wearable devices.

[0074] Take the computer device as a server as an example. Figure 1 A block diagram of a server is shown, such as Figure 1As shown, the server may include a processor and a memory connected via a system bus. The processor of the server is used to provide computing and control capabilities. The memory of the server includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. When the computer program is executed by the processor, a method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system is implemented.

[0075] Those skilled in the art will understand that Figure 1 The structure shown in the figure is only a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the server to which the solution of the present application is applied. Optionally, the server may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0076] It should be noted that the execution subject of the embodiments of the present application may be a computer device or a device for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system. The following method embodiments are described with a computer device as the execution subject.

[0077] Figure 2 A flow chart of the steps of a method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system provided in an embodiment of the present application. Figure 2 As shown, the method comprises the following steps:

[0078] Step 202: Obtain multiple groups of comparison test samples.

[0079] Among them, when obtaining multiple groups of comparative test samples, several groups of halogenated non-fullerene organic photovoltaic materials of similar systems can be selected first, and then the spin coating method is used to prepare comparative test samples of various sizes and qualities.

[0080] In some optional embodiments, when using the spin coating method, the polymer donor and the organic small molecule acceptor can be first dissolved independently in a chloroform solvent at a concentration of 16 mg / mL, which is the highest efficiency of the active layer of the photovoltaic device, and stirred overnight at room temperature in a glove box. Then, the donor and the acceptor are blended in a ratio of 1:2 to form three groups of non-halogenated, fluorinated, and chlorinated blended solutions, and ensure that the concentration of all blended solutions is 16 mg / mL. Before spin coating, the blended solution is stirred at a constant temperature of 35°C for 2 hours, and the organic mixed solution is spin-coated on a clean and blown quartz substrate with a thickness of 1 mm in an argon atmosphere glove box. The spin coater is set to a speed of 3000 rpm for 60 seconds. The freshly prepared blended film was immediately annealed at 110°C for 10 minutes, and the donor and acceptor pure films were prepared using the same concentration and the same procedure to obtain a comparison test sample. The oxygen-quenchable luminescent dye PtOEP was used as a triplet sensitizer, and the triplet sensitizer and the receptor were dissolved in chloroform solvent at a mass ratio of 1:4 to prepare a triplet sensitized sample with a concentration of 16 mg / mL.

[0081] It should be noted that the thickness of all samples should be kept basically the same, and the sample surface should be clean, flat, free of scratches and pollution, so as to ensure that when the subsequent pump light excites the sample, no scattering and diffraction interference signals unrelated to the photoelectric conversion dynamics are generated as much as possible.

[0082] Step 204 : for each group of comparison test samples, control the pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamics changes of the comparison test samples under preset excitation conditions to obtain two-dimensional spectral data.

[0083] Among them, after obtaining multiple groups of comparison test samples, the pre-built ultrafast transient absorption spectroscopy system can be controlled to measure the spectral dynamic changes of the comparison test samples under preset excitation conditions, thereby obtaining two-dimensional spectral data.

[0084] In some optional embodiments, the ultrafast transient absorption spectroscopy system may include a pump optical path module, a detection optical path module and a data acquisition module, such as Figure 3 As shown, Figure 3 A flowchart of steps for obtaining two-dimensional spectral data provided in an embodiment of the present application includes:

[0085] Step 302: Control the pump optical path module to generate pump light, so as to excite the test sample through pump light contrast.

[0086] Step 304 , control the detection light path module to generate detection light, so as to measure and compare the spectral dynamic changes of the test sample under the preset excitation conditions through the detection light to obtain two-dimensional spectral data.

[0087] Step 306: Control the data acquisition module to acquire two-dimensional spectral data, and send the two-dimensional spectral data to a computer device for processing.

[0088] Wherein, when generating pump light and detection light, optionally, as Figure 4 As shown, Figure 4 A flowchart of the steps of generating pump light and detection light provided in an embodiment of the present application includes:

[0089] Step 402: Control the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light.

[0090] Step 404 , controlling the beam splitter disposed at the output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam.

[0091] Step 406: Control the first light beam to generate pump light through the first nonlinear optical crystal in the pump light path module.

[0092] Step 408: Control the second light beam to converge onto the second nonlinear optical crystal through the flip mirror and the lens in the detection optical path module, and generate detection light through multiple nonlinear processes in the second nonlinear optical crystal.

[0093] The central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz. The pump light and detection light used in the ultrafast transient absorption spectroscopy system are both generated from the hundreds of femtosecond pulses output by a regenerative amplifier with a central wavelength of 800nm ​​and a repetition frequency of 5kHz.

[0094] At the output end of the regenerative amplifier, the hundred-femtosecond pulse light can be split by the beam splitter to obtain the first light beam and the second light beam, and the light intensity of the first light beam is greater than that of the second light beam. Therefore, the first light beam with a stronger light intensity can be placed in the pump light path module, and the pump light for exciting the sample can be generated through multiple nonlinear processes through the first nonlinear optical crystal. Among them, the first nonlinear optical crystal includes a barium metaborate crystal. It should be noted that the above-mentioned pump light path module generates a pump light spectrum that meets the experimental requirements through a non-collinear optical parametric amplifier (Non-Collinear Optical Parametric Amplifier, referred to as NOPA). According to the pump wavelength required by the experiment, different nonlinear action modes are selected to generate hundred-femtosecond pump pulses within 400nm to 800nm, which can be used to excite comparison test samples after modulation with an optical chopper.

[0095] Another second light beam with a weaker light intensity is converged to the second nonlinear optical crystal by a flip mirror through a lens, and a wide-spectrum supercontinuum detection pulse can be generated in the second nonlinear optical crystal through nonlinear processes such as self-focusing and self-phase modulation, generating supercontinuum white light in the visible band (500nm-1000nm) and near-infrared band (900nm-1600nm). The second nonlinear optical crystal includes yttrium aluminum garnet crystal, potassium titanyl phosphate crystal and sapphire crystal.

[0096] It should be noted that the detection optical path module uses a collinear parametric amplifier (OPA) to generate a narrowband pulse light source, and uses this light source to generate white light to expand the coverage of the detection light. The present invention uses a two-stage optical parametric amplification technology, in which the first-stage amplified seed light is used as the input of the second-stage optical parametric amplifier, thereby improving the light intensity and stability of the detection light to meet the precise excitation requirements of the sample. The design of these two modules can ensure the time resolution and signal-to-noise ratio of the spectral data.

[0097] Next, the supercontinuum white light is collected with a concave mirror and focused on the comparison test sample with a lens. After the detection pulse passes through the sapphire or yttrium aluminum garnet crystal, in order to subtract the influence of the false signal caused by the shaking of the detection white light itself, the white light can be divided into two beams through a beam splitter, one as signal light and the other as reference light. That is, the detection light includes signal light and reference light. The reference light is not affected by the pump light, that is, the reference light represents the change of the white light itself over time, which is used as the reference light intensity, thereby eliminating the influence of environmental noise and improving the measurement accuracy. By extending the detection supercontinuum white light band to the near infrared, a wider spectrum of spectral data can be obtained to meet the needs of more accurate and comprehensive carrier recombination dynamics measurement.

[0098] Thus, in some optional embodiments, such as Figure 5 As shown, Figure 5 Another step flow chart for obtaining two-dimensional spectral data provided in an embodiment of the present application includes:

[0099] Step 502: for the pump light under each preset excitation condition, control the detection light and the pump light to hit the comparison test sample, and control the signal light in the detection light to overlap with the pump light on the surface of the comparison test sample, block the pump light after passing through the comparison test sample, and obtain the detection light after passing through the comparison test sample.

[0100] Step 504 , controlling the detection light after passing through the comparison test sample to be transmitted to a spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0101] For the pump light under each preset excitation condition, the detection light and the pump light can be controlled to hit the comparison test sample, and the signal light in the detection light and the pump light can be controlled to overlap on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample, so as to obtain the detection light after passing through the comparison test sample. The preset excitation condition is determined according to the pump light wavelength, excitation position and excitation intensity of the pump light.

[0102] Therefore, the detection light after passing through the comparison test sample can be controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system. After the signal of the reference light is subtracted, the spectrum of the comparison test sample is read to obtain two-dimensional spectral data.

[0103] Optionally, to avoid polarization orientation relaxation in the excited sample, the comparison test sample is measured in a nitrogen atmosphere, and a half-wave plate is added to the detection light path, and the angle between the polarization direction of the pump light and the polarization direction of the detection light is set at a magic angle of 54.7°. In some optional embodiments, a mechanical delay line can be used to delay the fundamental frequency light that generates the pump light, and the relative time delay between the pump light and the detection light can be changed, so as to obtain the dynamics of transient spectral evolution and ensure the accuracy and reliability of the data.

[0104] In some optional embodiments, the transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

[0105] In some optional embodiments, the transient absorption measurement also includes nanosecond-resolved transient absorption measurement. The nanosecond-resolved transient absorption measurement generates a first signal and a second signal through a delayed signal generator DG645, and uses the delayed signal between the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

[0106] By utilizing the above two time-resolved measurements, the time delay range of spectral data can be effectively broadened, and dynamic information on the picosecond and nanosecond time scales can be provided, which is crucial for studying the ultrafast kinetics of organic photovoltaic excited-state energy conversion.

[0107] Step 206 : After data processing and comparison analysis of each set of two-dimensional spectral data, a comparison result of carrier dynamics of the halogenated non-fullerene organic photovoltaic system is generated.

[0108] The acquired two-dimensional spectral data can be tested and collected using Labview software. The data signal is represented by the differential change rate of transmittance, and the differential change rate of transmittance at different wavelengths and different time delays can be obtained to obtain the kinetic process of different components in the sample system.

[0109] In some optional embodiments, Figure 6 As shown, Figure 6 A flowchart of steps for generating a comparison result provided in an embodiment of the present application includes:

[0110] Step 602: for each group of two-dimensional spectral data, obtain an average value corresponding to a preset number of data points, and use the average value as an unexcited signal.

[0111] Step 604: After removing the unexcited signal from the two-dimensional spectrum data, perform transient absorption measurement, calculate the differential change rate of the transmittance of the comparison test sample to the detection light with and without pump light excitation, and use the differential change rate of the transmittance as the transient absorption signal.

[0112] Step 606: Compare the transient absorption signal with the preset steady-state absorption signal in a preset band and with a preset time delay to determine whether an intermediate state absorption signal is obtained.

[0113] Step 608: Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate absorption signal, the proportions of non-radiative recombination of charges in different systems are compared to obtain a comparison result of carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

[0114] The unstimulated signal may include an ambient light signal and an interference signal. Exemplarily, the preset number may be 10, so that the average value corresponding to ten data points may be collected in advance as the unstimulated signal.

[0115] Next, the transient absorption measurement can be performed after removing the unexcited signal from the two-dimensional spectral data, eliminating the influence of ambient stray light. The differential change rate of the transmittance of the comparison test sample to the detection light under pump light excitation and without pump light excitation is calculated by formula (1): The differential change rate of transmittance is taken as the transient absorption signal.

[0116]

[0117] Wherein, ε, l, c are the molar absorption coefficient, the thickness of the comparison test sample and the concentration of the comparison test sample respectively; ε′, c′ are the molar absorption coefficient and concentration after pump light excitation respectively; ΔT is the difference in transmittance between the comparison test sample excited by pump light and not excited by pump light in the transient absorption measurement experiment, T is the transmittance of the comparison test sample not excited by pump light in the transient absorption measurement experiment, λ is the wavelength of the detection light, t is the time, and i is the increment that changes with time.

[0118] The embodiment of the present application also provides a specific process of comparing multiple groups of test samples and conducting subsequent experiments. The polymer donor PM6, PBDB-T and the organic small molecule receptors Y5, Y6, and Y7 are independently dissolved in chloroform solvent at a concentration of 16 mg / mL, which is the highest efficiency of the active layer of the photovoltaic device, and stirred overnight at room temperature in the glove box. PM6 and PBDB-T are blended with Y5, Y6, and Y7 solutions in a ratio of 1:2 to form PBDB-T:Y5, PM6:Y6, and PM6:Y7 blended solutions, and the concentration of all blended solutions is ensured to be 16 mg / mL. Before spin coating, the blended solution is stirred at a constant temperature of 35°C for 2 hours, and the organic mixed solution is spin coated on a clean and blown quartz substrate with a thickness of 1 mm in an argon atmosphere glove box. The spin coater is set to a speed of 3000 rpm for 60 seconds. The newly prepared blended film was immediately annealed at 110°C for 10 minutes. Then, PM6, PBDB-T and Y5, Y6, and Y7 pure films were prepared using the same concentration and the same procedure, and three groups of comparative test samples were obtained. PtOEP was used as a triplet sensitizer and dissolved in chloroform solvent with a mass ratio of 1:4 in Y5, Y6, and Y7 to prepare triplet sensitized samples with a concentration of 16 mg / mL. The thickness of all samples was kept basically the same, and the sample surface was clean, flat, free of scratches and contamination, to ensure that the subsequent pump light excitation samples would not produce scattering and diffraction interference signals that were irrelevant to the photoelectric conversion dynamics as much as possible.

[0119] like Figure 7 As shown, Figure 7 A schematic diagram of the structure of an ultrafast transient absorption spectroscopy system provided in an embodiment of the present application. A is a barium borate crystal, i.e., a BBO crystal, B is a sapphire crystal, and C is a sapphire crystal or a yttrium aluminum garnet crystal, i.e., a YAG crystal. The ultrafast transient absorption spectroscopy system also includes a chopper and a detector.

[0120] When the pump light and the probe light are generated by the ultrafast transient absorption spectroscopy system, a regenerative amplifier with a central wavelength of 800nm ​​and a repetition frequency of 5kHz can output a hundred-femtosecond pulse light, and then use the elevation steering method to adjust the polarization direction to vertical, and then pass through a 1:9 beam splitter to be divided into two beams. The stronger beam passes through a delay line and is frequency-doubled to 400nm by a barium borate crystal, i.e., a BBO crystal. After filtering out the remaining 800nm ​​fundamental frequency light with a filter, the 400nm light is focused by a lens to a parametric amplification BBO crystal. The BBO crystal is 1-2cm behind the focus of the 400nm pump light to avoid damage to the crystal. After passing through a variable attenuation plate and an aperture, the weaker 800nm ​​light is focused by a lens to a 1.5mm sapphire crystal to generate supercontinuum white light as the signal light to be amplified.

[0121] Next, the generated supercontinuum white light passes through a Schottky glass filter and is incident on the BBO crystal at a specific angle using a concave mirror. When the pump light and the signal light overlap in time and space, a wide-spectrum output pulse is generated. Since the BBO crystal has the characteristic of spontaneously radiating superfluorescence in its phase matching direction under the irradiation of pump light, the phase matching direction of the BBO crystal is adjusted to gather all wavelengths of superfluorescence as much as possible, even if the superfluorescence ring is the thinnest. Then the signal light is coupled to the direction of superfluorescence radiation, which automatically meets the phase matching conditions of the ultra-wide spectrum. By slightly adjusting the time and space overlap, a specific wavelength of pump light can be obtained. Since it has passed through many dispersive media such as filters, the signal light pulse that has just been amplified has a large group delay dispersion. Due to the existence of group delay dispersion, it must be compressed to output an ultra-short pulse.

[0122] Optionally, in this experiment, a chirped mirror pair can be used to compress the pulse. A chirped mirror is a specially designed one-dimensional photonic crystal that can make long-wavelength light reflect at a deeper level of the mirror surface and short-wavelength light reflect at a shallower level of the mirror surface. This makes the optical path of long-wavelength light longer than that of short-wavelength light during the reflection process, thereby introducing negative group velocity dispersion. The compression is completed by simply reflecting the parametrically amplified pulse back and forth between the chirped mirror pair several times. Since the negative dispersion introduced by each reflection between the chirped mirror pair is a fixed value, in order to continuously adjust the compression amount, a set of optical wedge pairs with adjustable insertion amount are generally used simultaneously after the chirped mirror pair. Then the pump light is further collimated to enter the delay line to ensure that the optical path remains stable and does not shift when the delay line is adjusted to shift. The pump light passes through a chopper with a frequency of half the frequency of the output laser to control the spectrometer to determine whether the pump light passes through, thereby realizing the data acquisition cycle, and then passes through a polarizer, adjusts the polarization, and enters the nitrogen atmosphere sample stage.

[0123] The second beam of light is divided into two optical paths using a flip mirror frame, namely the visible detection part and the near-infrared detection part. Among them, the second beam of 800nm ​​fundamental frequency light is divided into three beams in the visible part through a beam splitter, one beam passes through a YAG crystal to generate seed light, another beam is used to pump the first-stage OPA, and the last beam is used to pump the second-stage OPA. The spatial overlap and temporal overlap are adjusted respectively, and an amplified light with a wavelength of 1300nm and a power density of about 4μJ is generated in the first-stage amplification, and an amplified light with a wavelength of 1300nm and a power density of about 24μJ is generated in the second-stage amplification. The amplified 1300nm light is further collimated and focused to generate a 500-950nm visible band wide-spectrum supercontinuum white light on the sapphire crystal as the detection light. After compression by a chirped mirror and filtering and intensity adjustment by an aperture and a filter, it is converged to the sample stage using a convex lens and a concave lens. When the flip mirror frame flips, the second beam of light passes through the lens and aperture and enters the YAG crystal to generate 950-1600nm near-infrared band supercontinuum white light, which is filtered and focused by the lens as the detection light. The detection light is divided into two beams of light through the beam splitter, namely signal light and reference light. As time changes, the white light is not affected by the pump light, and the reference light is used as the reference light intensity, thereby eliminating the influence of environmental noise and improving measurement accuracy.

[0124] The present application also provides a schematic diagram of the results of data processing of three groups of comparison test samples PBDB-T:Y5, PM6:Y6, and PM6:Y7, as shown in FIG. Figure 8-Figure 12 As shown, Figure 8 A schematic diagram of the comparison of transient spectra of a Y5 triplet sensitized sample obtained by sensitization and a comparison test sample at 1500ps provided in an embodiment of the present application, wherein the Y5 triplet sensitized sample is Y5:PtOEP, and T=1500ps indicates that the time delay is 1500ps. Fig. 9 A schematic diagram of the transient absorption dynamics of a power-dependent PBDB-T:Y5 comparison test sample provided in an embodiment of the present application, where T=1000ps indicates a time delay of 1000ps. Fig.10 A schematic diagram of the transient absorption spectra of three groups of comparison test samples PBDB-T:Y5, PM6:Y6 and PM6:Y7 when delayed by 1ns is provided in an embodiment of the present application, where T=1000ps means that the time delay is 1000ps, or 1ns. Fig.11 A schematic diagram of picosecond time-resolved kinetic curves of three groups of comparative test samples at 1450nm provided in an embodiment of the present application, Fig.12 A schematic diagram of nanosecond time-resolved kinetic curves of three groups of comparative test samples at 940nm and 1150nm provided in the embodiment of the present application. Figure 8-Figure 12 The data represented by the vertical axis are the normalized differential change rates of transmittance ( Δ T / T).

[0125] Among them, the steady-state absorption spectra of all comparison test samples and triplet sensitized samples have been measured, and the donor and acceptor of the comparison test samples were excited by pump light at a wavelength of 540nm and 730nm and a power density of 3.2μJ / cm2 to obtain two-dimensional spectral data. Ten data points were collected in advance as unexcited signals before the equal optical path point measurement. After averaging and subtracting the average value from the overall spectral data, the excited state signals of the remaining two-dimensional spectral data, such as transient spectra at different time delays such as 940nm and 1450nm, were extracted, and the intermediate state signals were determined by comparing the steady-state absorption signals.

[0126] It can be seen that the excited state absorption signal at 940nm is correspondingly enhanced. The excited state absorption signal generated at 940nm cannot be observed in the pure monomer film of the acceptor and donor, and the signal coexists with the ground state bleaching signal of the donor and acceptor, so it can be considered that this is the interface charge transfer state. After the interface charge transfer, the signal appears slightly red-shifted on a time scale of 30 to 200ps later, which indicates that the interface charge transfer state is further separated to form free charges, and the excited state absorption signal appears at 1450nm after decaying for 1ns.

[0127] Please continue to refer to Fig. 9 , by comparing the transient absorption test of the test samples with gradient power density of 1, 2, 4, 8, and 16μJ / cm2, and normalizing the data at the ground state bleaching signal generated at 940nm, the power dependence of the 1450nm signal can be obtained. Under higher pump power density, the spectral signal characteristics of 1450nm are more obvious, so it is believed that this signal process is a non-radiative recombination process. Then, the triplet sensitized sample is subjected to exactly the same pump detection to obtain its two-dimensional spectral data, and the data of the same unsensitized and sensitized samples at a delay of 1ns are extracted. After normalization, the characteristics at 1450nm match, which is considered to be a triplet signal.

[0128] The 1450nm signal at 1ns of the three groups of comparison test samples was extracted, and the signal intensity of the charge splitting intermediate state of each comparison test sample at 940nm was normalized to eliminate the influence of different comparison test samples on the charge splitting efficiency of pump light response. The signal was normalized again at 1ns when the signal appeared, and the triplet signal characteristics were compared. The differential change rate of the normalized transmittance ( Δ T / T) determines the ratio of triplet states in this process.

[0129] On the nanosecond scale, the signal is normalized at the maximum amplitude of the excited state absorption signal at 940nm, and the triplet lifetime comparison of different comparison test samples is obtained through double exponential fitting. Through the above data extraction, fitting and characterization processing, information such as the triplet lifetime and dynamic changes can be obtained, and the carrier recombination dynamics of the comparison test samples can be more accurately characterized to ensure the scientificity and consistency of the results.

[0130] The method for measuring the carrier dynamics of the halogenated non-fullerene organic photovoltaic system provided in this embodiment includes: obtaining multiple groups of comparison test samples, for each group of comparison test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamics changes of the comparison test samples under preset excitation conditions, obtaining two-dimensional spectral data, and performing data processing and comparison analysis on each group of two-dimensional spectral data to generate a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system. This scheme combines the ultrafast transient absorption spectroscopy technology to measure the carrier recombination dynamics of the halogenated non-fullerene organic photovoltaic system, which can realize the measurement and data analysis of the non-radiative recombination dynamics of different halogenated organic systems, and further improves the flexibility and accuracy of the measurement by using the pump-probe technology; in addition, the transient absorption spectroscopy system can be adjusted by a mechanical delay line, combined with a delay signal generator to achieve the required time domain resolution, and provide dynamic information on the picosecond and nanosecond time scales, which is convenient for studying the process of organic photoelectric conversion.

[0131] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0132] The present application also provides a device for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system, characterized in that the device comprises an ultrafast transient absorption spectroscopy system and a computer device, and the ultrafast transient absorption spectroscopy system and the computer device are communicatively connected, wherein:

[0133] The ultrafast transient absorption spectroscopy system is used to obtain multiple groups of comparison test samples; for each group of comparison test samples, the spectral dynamics changes of the comparison test samples under preset excitation conditions are measured to obtain two-dimensional spectral data, and the two-dimensional spectral data is sent to the computer device;

[0134] The computer equipment is used to obtain each group of two-dimensional spectral data, and after data processing and comparative analysis of each group of two-dimensional spectral data, generate a comparison result of carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

[0135] Regarding the device in the above embodiment, the specific implementation manner and beneficial effects can be referred to the detailed description of the above method embodiment, which will not be repeated here.

[0136] In one embodiment of the present application, a computer device is provided, the computer device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the following steps when executing the computer program:

[0137] Obtain multiple groups of comparative test samples;

[0138] For each group of comparison test samples, the pre-built ultrafast transient absorption spectroscopy system is controlled to measure the spectral dynamic changes of the comparison test samples under preset excitation conditions to obtain two-dimensional spectral data;

[0139] After data processing and comparative analysis of each group of two-dimensional spectral data, the comparison results of carrier dynamics of halogenated non-fullerene organic photovoltaic system are generated.

[0140] In one embodiment of the present application, when the processor executes the computer program, the processor further implements the following steps:

[0141] Controlling the pump optical path module to generate pump light, so as to excite the test sample through pump light contrast;

[0142] Controlling the detection light path module to generate detection light, so as to measure and compare the spectral dynamics changes of the test sample under the preset excitation conditions through the detection light, and obtain two-dimensional spectral data; wherein the preset excitation conditions are determined according to the pump light wavelength, excitation position and excitation intensity of the pump light;

[0143] The data acquisition module is controlled to acquire two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device for processing.

[0144] In one embodiment of the present application, when the processor executes the computer program, the processor further implements the following steps:

[0145] Controlling the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light; wherein the central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz;

[0146] Controlling a beam splitter disposed at an output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam; wherein the light intensity of the first light beam is greater than the light intensity of the second light beam;

[0147] Controlling the first light beam to generate pump light through a first nonlinear optical crystal in a pump optical path module; the first nonlinear optical crystal comprises a barium metaborate crystal;

[0148] The second light beam is controlled to converge onto the second nonlinear optical crystal through the flip mirror and the lens in the detection optical path module, and the detection light is generated in the second nonlinear optical crystal through multiple nonlinear processes; wherein the detection light includes signal light and reference light, the reference light is not affected by the pump light, and the second nonlinear optical crystal includes yttrium aluminum garnet crystal, potassium titanyl phosphate crystal and sapphire crystal.

[0149] In one embodiment of the present application, when the processor executes the computer program, the processor further implements the following steps:

[0150] For the pump light under each preset excitation condition, the detection light and the pump light are controlled to hit the comparison test sample, and the signal light in the detection light is controlled to overlap with the pump light on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample to obtain the detection light after passing through the comparison test sample;

[0151] The detection light after passing through the comparison test sample is controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0152] In one embodiment of the present application, when the processor executes the computer program, the processor further implements the following steps:

[0153] For each group of two-dimensional spectral data, an average value corresponding to a preset number of data points is obtained, and the average value is used as an unexcited signal; wherein the unexcited signal includes an ambient light signal and an interference signal;

[0154] After removing the unexcited signal from the two-dimensional spectrum data, transient absorption measurement is performed, and the differential change rate of the transmittance of the comparison test sample to the detection light under pump light excitation and without pump light excitation is calculated, and the differential change rate of the transmittance is used as the transient absorption signal;

[0155] Comparing the transient absorption signal with the preset steady-state absorption signal in a preset band and with a preset time delay to determine whether an intermediate state absorption signal is obtained;

[0156] Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate state absorption signal, the proportion of non-radiative recombination of charges in different systems is compared, and the comparison results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system are obtained.

[0157] In one embodiment of the present application, the transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

[0158] In one embodiment of the present application, the transient absorption measurement also includes nanosecond-resolved transient absorption measurement. The nanosecond-resolved transient absorption measurement generates a first signal and a second signal through a delayed signal generator, and uses the delayed signal between the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

[0159] The computer device provided in the embodiment of the present application has similar implementation principles and technical effects to those of the above-mentioned method embodiment, and will not be described in detail here.

[0160] In one embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0161] Obtain multiple groups of comparative test samples;

[0162] For each group of comparison test samples, the pre-built ultrafast transient absorption spectroscopy system is controlled to measure the spectral dynamic changes of the comparison test samples under preset excitation conditions to obtain two-dimensional spectral data;

[0163] After data processing and comparative analysis of each group of two-dimensional spectral data, the comparison results of carrier dynamics of halogenated non-fullerene organic photovoltaic system are generated.

[0164] In one embodiment of the present application, when the computer program is executed by a processor, the following steps are further implemented:

[0165] Controlling the pump optical path module to generate pump light, so as to excite the test sample through pump light contrast;

[0166] Controlling the detection light path module to generate detection light, so as to measure and compare the spectral dynamics changes of the test sample under the preset excitation conditions through the detection light, and obtain two-dimensional spectral data; wherein the preset excitation conditions are determined according to the pump light wavelength, excitation position and excitation intensity of the pump light;

[0167] The data acquisition module is controlled to acquire two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device for processing.

[0168] In one embodiment of the present application, when the computer program is executed by a processor, the following steps are further implemented:

[0169] Controlling the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light; wherein the central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz;

[0170] Controlling a beam splitter disposed at an output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam; wherein the light intensity of the first light beam is greater than the light intensity of the second light beam;

[0171] Controlling the first light beam to generate pump light through a first nonlinear optical crystal in a pump optical path module; the first nonlinear optical crystal comprises a barium metaborate crystal;

[0172] The second light beam is controlled to converge onto the second nonlinear optical crystal through the flip mirror and the lens in the detection optical path module, and the detection light is generated in the second nonlinear optical crystal through multiple nonlinear processes; wherein the detection light includes signal light and reference light, the reference light is not affected by the pump light, and the second nonlinear optical crystal includes yttrium aluminum garnet crystal, potassium titanyl phosphate crystal and sapphire crystal.

[0173] In one embodiment of the present application, when the computer program is executed by a processor, the following steps are further implemented:

[0174] For the pump light under each preset excitation condition, the detection light and the pump light are controlled to hit the comparison test sample, and the signal light in the detection light is controlled to overlap with the pump light on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample to obtain the detection light after passing through the comparison test sample;

[0175] The detection light after passing through the comparison test sample is controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0176] In one embodiment of the present application, when the computer program is executed by a processor, the following steps are further implemented:

[0177] For each group of two-dimensional spectral data, an average value corresponding to a preset number of data points is obtained, and the average value is used as an unexcited signal; wherein the unexcited signal includes an ambient light signal and an interference signal;

[0178] After removing the unexcited signal from the two-dimensional spectrum data, transient absorption measurement is performed, and the differential change rate of the transmittance of the comparison test sample to the detection light under pump light excitation and without pump light excitation is calculated, and the differential change rate of the transmittance is used as the transient absorption signal;

[0179] Comparing the transient absorption signal with the preset steady-state absorption signal in a preset band and with a preset time delay to determine whether an intermediate state absorption signal is obtained;

[0180] Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate state absorption signal, the proportion of non-radiative recombination of charges in different systems is compared, and the comparison results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system are obtained.

[0181] In one embodiment of the present application, the transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

[0182] In one embodiment of the present application, the transient absorption measurement also includes nanosecond-resolved transient absorption measurement. The nanosecond-resolved transient absorption measurement generates a first signal and a second signal through a delayed signal generator, and uses the delayed signal between the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

[0183] The computer-readable storage medium provided in this embodiment has similar implementation principles and technical effects to those of the above method embodiments, and will not be described in detail here.

[0184] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0185] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0186] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for measuring carrier dynamics of a halogenated non-fullerene organic photovoltaic system, characterized in that: The method comprises: Obtain multiple groups of comparative test samples; For each group of the comparison test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamics changes of the comparison test samples under preset excitation conditions to obtain two-dimensional spectral data; After data processing and comparative analysis of each group of the two-dimensional spectral data, a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system is generated.

2. The method according to claim 1, characterized in that: The ultrafast transient absorption spectroscopy system includes a pump optical path module, a detection optical path module and a data acquisition module. The control pre-built ultrafast transient absorption spectroscopy system measures the spectral dynamics changes of the comparison test sample under preset excitation conditions to obtain two-dimensional spectral data, including: Controlling the pump optical path module to generate pump light, so as to excite the comparison test sample through the pump light; Controlling the detection light path module to generate detection light, so as to measure the spectral dynamic changes of the comparison test sample under preset excitation conditions through the detection light, and obtain two-dimensional spectral data; wherein the preset excitation conditions are determined according to the pump light wavelength, excitation position and excitation intensity of the pump light; The data acquisition module is controlled to acquire the two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device for processing.

3. The method according to claim 2, characterized in that The method further comprises: Controlling the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output hundreds of femtosecond pulse light; wherein the central wavelength of the regenerative amplifier is 800nm ​​and the repetition frequency is 5kHz; Controlling a beam splitter disposed at an output end of the regenerative amplifier to split the hundred-femtosecond pulse light to obtain a first light beam and a second light beam; wherein the light intensity of the first light beam is greater than the light intensity of the second light beam; Controlling the first light beam to generate the pump light through a first nonlinear optical crystal in the pump optical path module; the first nonlinear optical crystal comprises a barium metaborate crystal; The second light beam is controlled to converge onto a second nonlinear optical crystal through a flip mirror and a lens in the detection optical path module, and detection light is generated in the second nonlinear optical crystal through a plurality of nonlinear processes; wherein the detection light includes a signal light and a reference light, the reference light is not affected by the pump light, and the second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanyl phosphate crystal and a sapphire crystal.

4. The method according to claim 3, characterized in that The step of measuring the spectral dynamics changes of the comparison test sample under preset excitation conditions by the detection light to obtain two-dimensional spectral data includes: For the pump light under each preset excitation condition, the detection light and the pump light are controlled to hit the comparison test sample, and the signal light in the detection light is controlled to overlap with the pump light on the surface of the comparison test sample, and the pump light is blocked after passing through the comparison test sample to obtain the detection light after passing through the comparison test sample; The detection light after passing through the comparison test sample is controlled to be transmitted to a spectrometer in an ultrafast transient absorption spectroscopy system to obtain the two-dimensional spectral data.

5. The method according to any one of claims 1 to 4, characterized in that: After processing and comparing the two-dimensional spectral data of each group, a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system is generated, including: For each group of the two-dimensional spectral data, an average value corresponding to a preset number of data points is obtained, and the average value is used as an unexcited signal; wherein the unexcited signal includes an ambient light signal and an interference signal; After removing the unexcited signal from the two-dimensional spectrum data, transient absorption measurement is performed, and the differential change rate of the transmittance of the comparison test sample to the detection light under the conditions of pump light excitation and no pump light excitation is calculated, and the differential change rate of the transmittance is used as the transient absorption signal; Comparing the transient absorption signal with a preset steady-state absorption signal in a preset band and with a preset time delay to determine an intermediate state absorption signal; Based on the transient absorption signal, the preset steady-state absorption signal and the intermediate state absorption signal, the proportions of non-radiative recombination of charges in different systems are compared to obtain a comparison result of carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

6. The method according to claim 5, characterized in that The transient absorption measurement includes picosecond-resolved transient absorption measurement, which utilizes a mechanical delay line to perform optical path delay and can achieve picosecond resolution.

7. The method according to claim 5, characterized in that The transient absorption measurement also includes nanosecond-resolved transient absorption measurement, which generates a first signal and a second signal through a delayed signal generator, and uses the delayed signal in the first signal and the second signal as a trigger signal for a nanosecond laser to achieve nanosecond resolution.

8. A device for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system, characterized in that: The device comprises an ultrafast transient absorption spectroscopy system and a computer device, wherein the ultrafast transient absorption spectroscopy system and the computer device are communicatively connected, wherein: The ultrafast transient absorption spectroscopy system is used to obtain multiple groups of comparison test samples; for each group of the comparison test samples, the spectral dynamics changes of the comparison test samples under preset excitation conditions are measured to obtain two-dimensional spectral data, and the two-dimensional spectral data are sent to a computer device; The computer device is used to obtain each group of the two-dimensional spectral data, and after data processing and comparison analysis of each group of the two-dimensional spectral data, generate a comparison result of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

9. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the steps of the method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the steps of the method described in any one of claims 1 to 7.

Images