Measurement methods for carrier dynamics in halogenated non-fullerene organic photovoltaic systems

Abstract

This application discloses a method for measuring carrier dynamics in halo-based non-fullerene organic photovoltaic systems. This method combines ultrafast transient absorption spectroscopy with other techniques to measure carrier recombination dynamics in halo-based non-fullerene organic photovoltaic systems. This method enables the measurement and data analysis of non-radiative recombination dynamics in different halo-based organic systems. Furthermore, the pump-probe technique is used to further improve the flexibility and accuracy of the measurement. In addition, the transient absorption spectroscopy system can be adjusted by mechanical delay lines and combined with a delay signal generator to achieve the required time-domain resolution, providing dynamic information on picosecond and nanosecond timescales, which is convenient for studying the organic photoelectric conversion process.

Description

Technical Field

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

[0002] In recent years, polymer-based organic solar cells have attracted widespread attention. Compared with traditional inorganic semiconductors, these organic polymer solar cells have advantages such as simple fabrication processes, flexibility, low cost, and a wide range of applications. Currently, non-fullerene acceptor materials have become a research hotspot in the application of organic solar cells. These materials are gradually replacing traditional fullerene acceptors due to their superior performance and ease of control.

[0003] Currently, 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 picosecond or even shorter timescales. However, existing technologies cannot achieve the measurement of carrier dynamics in halogenated non-fullerene organic photovoltaic systems. Summary of the Invention

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

[0005] Obtain multiple sets of comparative test samples;

[0006] For each group of comparative test samples, a pre-built ultrafast transient absorption spectroscopy system was controlled to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions, and two-dimensional spectral data were obtained.

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

[0008] In one possible implementation, the ultrafast transient absorption spectroscopy system includes a pump optical path module, a probe optical path module, and a data acquisition module. The system 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, obtaining two-dimensional spectral data, including:

[0009] The pump light path module is controlled to generate pump light, so as to excite the test sample by pump light comparison;

[0010] The detection optical path module generates detection light to measure and compare the spectral dynamics changes of the test sample under preset excitation conditions, thereby obtaining two-dimensional spectral data. The preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity.

[0011] The control data acquisition module collects two-dimensional spectral data and sends the two-dimensional spectral data to a computer device for processing.

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

[0013] The regenerative amplifier in the ultrafast transient absorption spectroscopy system is controlled to output 100 femtosecond pulses of light; wherein the center wavelength of the regenerative amplifier is 800 nm and the repetition frequency is 5 kHz;

[0014] A beam splitter at the output of a regenerative amplifier is used to split the femtosecond pulse light to obtain a first beam and a second beam; wherein the light intensity of the first beam is greater than that of the second beam.

[0015] The first beam is controlled to generate pump light through a first nonlinear optical crystal in the pump optical path module; the first nonlinear optical crystal includes a barium metaborate crystal.

[0016] The second beam is controlled to be focused onto the second nonlinear optical crystal by a flip mirror and a lens in the probe optical path module. The probe light is generated in the second nonlinear optical crystal through a variety of nonlinear processes. The probe light includes a signal light and a reference light. The reference light is not affected by the pump light. The second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanate phosphate crystal, and a sapphire crystal.

[0017] In one possible implementation, two-dimensional spectral data is obtained by measuring and comparing the spectral dynamics changes of the test sample under preset excitation conditions using probe light, including:

[0018] For pump light under various preset excitation conditions, both the probe light and the pump light are controlled to hit the comparison test sample. The signal light in the probe light and the pump light are controlled to coincide on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, and the probe light after passing through the comparison test sample is obtained.

[0019] The probe light transmitted through the 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 one possible implementation, after data processing and comparative analysis of each group of two-dimensional spectral data, comparative results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system are generated, including:

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

[0022] After removing the unexcited signal from the two-dimensional spectral data, transient absorption measurements were performed. The differential rate of change of the transmittance of the comparative test sample to the probe light under pump light excitation and without pump light excitation was calculated, and the differential rate of change of transmittance was used as the transient absorption signal.

[0023] The transient absorption signal is compared with the preset steady-state absorption signal under a preset band and a preset time delay to determine the intermediate state absorption signal;

[0024] Based on transient absorption signals, preset steady-state absorption signals, and intermediate-state absorption signals, the comparison results of the carrier dynamics of halogenated non-fullerene organic photovoltaic systems are obtained by comparing the proportion of non-radiative charge recombination in different systems.

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

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

[0027] The second aspect of this application proposes a measurement device for carrier dynamics of a halogenated non-fullerene organic photovoltaic system. The device includes an ultrafast transient absorption spectroscopy system and a computer device, with a communication connection between the ultrafast transient absorption spectroscopy system and the computer device, wherein:

[0028] An ultrafast transient absorption spectroscopy system is used to acquire multiple sets of comparative test samples; for each set of comparative test samples, the spectral dynamics changes of the comparative test samples under preset excitation conditions are measured to obtain two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device;

[0029] Computer equipment is used to acquire each set of two-dimensional spectral data, and after processing and comparing the data, generate comparison results of carrier dynamics of halogenated non-fullerene organic photovoltaic systems.

[0030] In one possible implementation, the ultrafast transient absorption spectroscopy system includes a pump optical path module, a probe optical path module, and a data acquisition module. The ultrafast transient absorption spectroscopy system is also used for:

[0031] The pump light path module is controlled to generate pump light, so as to excite the test sample by pump light comparison;

[0032] The detection optical path module generates detection light to measure and compare the spectral dynamics changes of the test sample under preset excitation conditions, thereby obtaining two-dimensional spectral data. The preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity.

[0033] The control data acquisition module collects two-dimensional spectral data and sends the two-dimensional spectral data to a computer device for processing.

[0034] In one possible implementation, the aforementioned device for measuring carrier dynamics in the halogenated non-fullerene organic photovoltaic system is also used for:

[0035] The regenerative amplifier in the ultrafast transient absorption spectroscopy system is controlled to output 100 femtosecond pulses of light; wherein the center wavelength of the regenerative amplifier is 800 nm and the repetition frequency is 5 kHz;

[0036] A beam splitter at the output of a regenerative amplifier is used to split the femtosecond pulse light to obtain a first beam and a second beam; wherein the light intensity of the first beam is greater than that of the second beam.

[0037] The first beam is controlled to generate pump light through a first nonlinear optical crystal in the pump optical path module; the first nonlinear optical crystal includes a barium metaborate crystal.

[0038] The second beam is controlled to be focused onto the second nonlinear optical crystal by a flip mirror and a lens in the probe optical path module. The probe light is generated in the second nonlinear optical crystal through a variety of nonlinear processes. The probe light includes a signal light and a reference light. The reference light is not affected by the pump light. The second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanate phosphate crystal, and a sapphire crystal.

[0039] In one possible implementation, the above-described ultrafast transient absorption spectroscopy system is also used for:

[0040] For pump light under various preset excitation conditions, both the probe light and the pump light are controlled to hit the comparison test sample. The signal light in the probe light and the pump light are controlled to coincide on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, and the probe light after passing through the comparison test sample is obtained.

[0041] The probe light transmitted through the 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 one possible implementation, the above-described computer device is specifically used for:

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

[0044] After removing the unexcited signal from the two-dimensional spectral data, transient absorption measurements were performed. The differential rate of change of the transmittance of the comparative test sample to the probe light under pump light excitation and without pump light excitation was calculated, and the differential rate of change of transmittance was used as the transient absorption signal.

[0045] The transient absorption signal is compared with the preset steady-state absorption signal under a preset band and a preset time delay to determine the intermediate state absorption signal;

[0046] Based on transient absorption signals, preset steady-state absorption signals, and intermediate-state absorption signals, the comparison results of the carrier dynamics of halogenated non-fullerene organic photovoltaic systems are obtained by comparing the proportion of non-radiative charge recombination in different systems.

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

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

[0049] A third aspect of this application provides an electronic device comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, wherein 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 nonfullerene organic photovoltaic system as described in the first aspect.

[0050] The fourth aspect of this application proposes a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein 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 this application have the following beneficial effects:

[0052] The method for measuring carrier dynamics of halogenated non-fullerene organic photovoltaic systems provided in this application includes: acquiring multiple sets of comparative test samples; for each set of comparative test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamic changes of the comparative test samples under preset excitation conditions to obtain two-dimensional spectral data; and generating comparative results of carrier dynamics of halogenated non-fullerene organic photovoltaic systems after data processing and comparative analysis of each set of two-dimensional spectral data. This scheme, by combining ultrafast transient absorption spectroscopy technology to measure carrier recombination dynamics of halogenated non-fullerene organic photovoltaic systems, can realize the measurement and data analysis of non-radiative recombination dynamics of different halogenated organic systems. Furthermore, the pump-probe technique further enhances the flexibility and accuracy of the measurement. In addition, the transient absorption spectroscopy system can achieve the required time-domain resolution through mechanical delay line adjustment, combined with a delay signal generator, providing dynamic information on picosecond and nanosecond timescales, facilitating the study of organic photoelectric conversion processes. Attached Figure Description

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

[0054] Figure 2 A flowchart illustrating the steps of a method for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system provided in this application embodiment;

[0055] Figure 3 A flowchart illustrating the steps for obtaining two-dimensional spectral data is provided in this application embodiment.

[0056] Figure 4 A flowchart illustrating the steps for generating pump light and probe light is provided in this application embodiment;

[0057] Figure 5 A flowchart illustrating another step for obtaining two-dimensional spectral data provided in this application embodiment;

[0058] Figure 6 A flowchart illustrating the steps for generating alignment results provided in this application embodiment;

[0059] Figure 7 This is a schematic diagram of the structure of an ultrafast transient absorption spectroscopy system provided in an embodiment of this application;

[0060] Figure 8 A schematic diagram comparing the transient spectra of a Y5 triplet sensitized sample obtained by sensitization with a comparative test sample at 1500 ps, ​​provided in an embodiment of this application.

[0061] Figure 9 A schematic diagram of transient absorption kinetics of a power-dependent PBDB-T:Y5 alignment test sample provided in this application embodiment;

[0062] Figure 10 A schematic diagram of the transient absorption spectra of three sets of comparative test samples, PBDB-T:Y5, PM6:Y6 and PM6:Y7, after a 1ns delay, provided for an embodiment of this application;

[0063] Figure 11 A schematic diagram of picosecond time-resolved dynamics curves of three sets of comparative test samples at 1450 nm provided for an embodiment of this application;

[0064] Figure 12 This is a schematic diagram of nanosecond time-resolved dynamics curves of three sets of comparative test samples at 940nm and 1150nm, provided as an embodiment of this application. Detailed Implementation

[0065] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort 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, these organic polymer solar cells have advantages such as simple fabrication processes, flexibility, low cost, and diverse applications. The application of non-fullerene acceptors has further improved the efficiency of organic solar cells, with the highest reported efficiency exceeding 20%. Since the synthesis and application of non-fullerene acceptors, the power conversion efficiency of OSCs has been continuously improving. These acceptors have exhibited top-notch photovoltaic performance. The conversion efficiency of non-fullerene acceptor (NFAs) organic solar cells has been significantly improved, thanks to the advantages of NFAs, such as wider absorption spectrum coverage, longer excitation-diffusion length, and reduced non-radiative recombination loss. 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 acceptors affect the photoelectric performance of organic solar cell devices. Currently, researchers are using various control methods (such as end group engineering, side chain engineering, and framework engineering) to modify the structure of non-fullerene small molecule acceptors, designing and synthesizing a series of highly efficient NFAs. On the one hand, the electron-pull effect within organic acceptor molecules is influenced by the electron-withdrawing ability of the end groups; on the other hand, the stacking between organic acceptor molecules mainly depends on the interaction between the end groups and the molecules. Therefore, end group modification is one of the effective ways to control the spectral absorption, energy levels, and crystallization behavior of acceptor molecules. By introducing electron-withdrawing halogen atoms such as F and Cl atoms into the end groups, the optical band gap can usually be narrowed, the energy level lowered, the intermolecular interaction increased, and charge transport improved, which is beneficial for obtaining higher short-circuit current and fill factor. In addition, F atoms have high electronegativity and can form α and β interactions and non-covalent interactions in the molecule, promoting charge transport.

[0068] Exploring the dynamics of photovoltaic materials in the excited state, especially the generation and recombination mechanisms of photogenerated charges, is crucial for understanding the working mechanism of photovoltaic devices and overcoming obstacles limiting their performance improvement. Ultrafast spectroscopy, capable of monitoring the non-equilibrium dynamic changes of materials in the excited state under photoexcitation across the entire timescale, is a key tool for studying the excited-state dynamics of organic photovoltaic materials. Compared to fullerene acceptor systems, NFA systems exhibit unique excited-state characteristics. In the photoelectric conversion channels of polymer / NFA systems, the simultaneous occurrence of electron and hole transfer channels allows NFA systems to achieve conversion under very small interfacial potential differences.

[0069] From the perspective of charge loss and energy loss, multiple different energy loss mechanisms exist simultaneously in non-fullerene acceptor photovoltaic devices. The generation and recombination of triplet states are two key dynamic processes affecting effective charge splitting. The generation of triplet excitons (T1) typically occurs through intersystem crossing (ISC) of singlet excitons, a transition from singlet (S1) to triplet (T1). Triplet recombination involves the interaction between triplet excitons and charge carriers (such as electrons or holes), leading to nonradiative energy loss of the excitons. Current technologies cannot measure the carrier dynamics of halide-based non-fullerene organic photovoltaic systems.

[0070] Based on this, this application proposes a method for measuring carrier dynamics in halogenated non-fullerene organic photovoltaic systems. The method includes: acquiring multiple sets of comparative test samples; for each set of comparative test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamic changes of the comparative test samples under preset excitation conditions, obtaining two-dimensional spectral data; and after data processing and comparative analysis of each set of two-dimensional spectral data, generating comparative results of carrier dynamics in the halogenated non-fullerene organic photovoltaic system. This method, by combining ultrafast transient absorption spectroscopy with a method for measuring carrier recombination dynamics in halogenated non-fullerene organic photovoltaic systems, can achieve the measurement and data analysis of non-radiative recombination dynamics of different halogenated organic systems. Furthermore, the pump-probe technique further enhances the flexibility and accuracy of the measurement. In addition, the transient absorption spectroscopy system can be adjusted via a mechanical delay line, combined with a delay signal generator, to achieve the required time-domain resolution, providing dynamic information on picosecond and nanosecond timescales, facilitating the study of organic photoelectric conversion processes.

[0071] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0072] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, the use of "based on" or "according to" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" or "according to" one or more of the stated conditions or values ​​may in practice be based on additional conditions or beyond the stated values.

[0073] The method for measuring carrier dynamics of halogenated non-fullerene organic photovoltaic systems provided in this application can be applied to computer equipment (electronic devices). The computer equipment can be a server or a terminal. The server can be a single server or a server cluster composed of multiple servers. This application does not specifically limit this. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices.

[0074] Taking a computer device 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 memory connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. When the computer program is executed by the processor, it implements a method for measuring the carrier dynamics of a halide-based non-fullerene organic photovoltaic system.

[0075] Those skilled in the art will understand that Figure 1 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the server to which 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 different component arrangements.

[0076] It should be noted that the execution subject of the embodiments of this application can be a computer device or a measurement device for carrier dynamics of halogenated non-fullerene organic photovoltaic systems. The following method embodiments will be described with a computer device as the execution subject.

[0077] Figure 2 This is a flowchart illustrating the steps of a method for measuring carrier dynamics in a haloform non-fullerene organic photovoltaic system, as provided in an embodiment of this application. Figure 2 As shown, the method includes the following steps:

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

[0079] When obtaining multiple sets of comparative test samples, several sets of halogenated non-fullerene organic photovoltaic materials with similar systems can be selected first, and then a variety of comparative test samples of different sizes and masses can be prepared by spin coating.

[0080] In some alternative embodiments, when using spin coating, the polymer donor and the small organic molecule acceptor can first be independently dissolved in chloroform at a concentration of 16 mg / mL, which maximizes the efficiency of the photovoltaic active layer, and stirred overnight at room temperature in a glove box. Next, the donor and acceptor are blended separately at a 1:2 ratio to prepare three sets of unhalogenated, unfluorinated, and unchlorinated blend solutions, ensuring that the concentration of all blend solutions is 16 mg / mL. Before spin coating, the blend solutions are stirred at a constant temperature of 35°C for 2 hours. The organic mixture is then spin-coated onto a clean, dried 1 mm thick quartz substrate in an argon-atmosphere glove box at a spin coater speed of 3000 rpm for 60 seconds. The freshly prepared blend film is immediately annealed at 110°C for 10 minutes. Pure donor and acceptor films are then prepared using the same concentration and procedure to obtain the comparison test sample. The oxygen-quenchable luminescent dye PtOEP was used as a triplet sensitizer. The triplet sensitizer and the acceptor were dissolved in chloroform solvent at a mass ratio of 1:4 to prepare triplet sensitized samples with a concentration of 16 mg / mL.

[0081] It should be noted that all samples should be kept at a relatively uniform thickness, and the sample surfaces should be clean, flat, and free of scratches and contamination. This will ensure that when the samples are subsequently excited by pump light, scattering and diffraction interference signals that are unrelated to photoelectric conversion dynamics are minimized.

[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, and obtain two-dimensional spectral data.

[0083] After acquiring multiple sets of comparative test samples, a pre-built ultrafast transient absorption spectroscopy system can be controlled to measure the spectral dynamics changes of the comparative 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 probe 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 this application embodiment includes:

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

[0086] Step 304: Control the detection optical path module to generate detection light, so as to measure and compare the spectral dynamic changes of the test sample under preset excitation conditions through the detection light, and 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 the computer device for processing.

[0088] In generating pump light and probe light, optionally, such as Figure 4 As shown, Figure 4 A flowchart illustrating the steps for generating pump light and probe light, provided in this application embodiment, includes:

[0089] Step 402: Control the regenerative amplifier in the ultrafast transient absorption spectroscopy system to output 100 femtosecond pulse light.

[0090] Step 404: Control the beam splitter set at the output of the regenerative amplifier to split the 100 femtosecond pulse light to obtain the first beam and the second beam.

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

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

[0093] The regenerative amplifier has a center wavelength of 800 nm and a repetition frequency of 5 kHz. The pump light and probe light used in the ultrafast transient absorption spectroscopy system are both generated from the 100 femtosecond pulse light output by a regenerative amplifier with a center wavelength of 800 nm and a repetition frequency of 5 kHz.

[0094] At the output of the regenerative amplifier, the femtosecond pulse light can be split by a beam splitter to obtain a first beam and a second beam, with the intensity of the first beam being greater than that of the second beam. The stronger first beam can then be used in the pump optical path module to generate pump light for exciting the sample through multiple nonlinear processes via a first nonlinear optical crystal. This first nonlinear optical crystal includes a barium metaborate crystal. It should be noted that the pump optical path module generates a pump light spectrum that meets experimental requirements via a non-collinear optical parametric amplifier (NOPA). By selecting different nonlinear interaction modes according to the required pump wavelength, femtosecond pump pulses within the range of 400 nm to 800 nm can be generated, which, after modulation with an optical chopper, can be used to excite and compare test samples.

[0095] A weaker second beam is focused onto a second nonlinear optical crystal via a flip mirror and lens. Within this crystal, nonlinear processes such as self-focusing and self-phase modulation generate a broadband supercontinuum detector pulse, producing supercontinuum white light in the visible (500nm–1000nm) and near-infrared (900nm–1600nm) bands. The second nonlinear optical crystal comprises yttrium aluminum garnet, potassium titanium oxyphosphate, and sapphire crystals.

[0096] It should be noted that the probe optical path module uses an optical parametric amplifier (OPA) to generate a narrowband pulsed light source, which is then used to produce white light to extend the coverage of the probe light. This invention employs a two-stage optical parametric amplification technique, where the seed light amplified in the first stage serves as the input to the second-stage optical parametric amplifier, thereby improving the intensity and stability of the probe light to meet the requirements for precise sample excitation. The design of these two modules ensures the time resolution and signal-to-noise ratio of the spectral data.

[0097] Next, a concave mirror is used to collect the supercontinuum white light, which is then focused onto the comparison test sample using a lens. After the probe pulse passes through a sapphire or yttrium aluminum garnet crystal, to reduce the influence of spurious signals caused by the fluctuation of the probe white light itself, the white light can be split into two beams by a beam splitter: one beam serves as the signal light, and the other as the reference light. In other words, the probe light includes both the signal and reference beams. The reference beam is unaffected by the pump light; it represents the change of the white light itself over time and serves as the reference intensity, thereby eliminating the influence of environmental noise and improving measurement accuracy. By extending the probe supercontinuum white light wavelength range to the near-infrared, a wider spectral range is obtained, meeting the needs for more accurate and comprehensive carrier recombination dynamics measurements.

[0098] Thus, in some alternative embodiments, such as Figure 5 As shown, Figure 5 Another flowchart of steps for obtaining two-dimensional spectral data provided in this application embodiment includes:

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

[0100] Step 504: Control the transmission of the probe light after passing through the comparison test sample to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain two-dimensional spectral data.

[0101] Specifically, for the pump light under each preset excitation condition, both the probe light and the pump light can be controlled to strike the comparison test sample. The signal light in the probe light and the pump light are then controlled to overlap on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, thus obtaining the probe light that has passed through the comparison test sample. The preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity.

[0102] Therefore, the probe light transmitted through the comparison test sample can be controlled to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system. After subtracting the signal of the reference light, the spectrum transmitted through the comparison test sample can be read, thereby obtaining two-dimensional spectral data.

[0103] Optionally, to avoid polarization orientation relaxation within the excited sample, the comparison test sample is measured in a nitrogen atmosphere, and a half-wave plate is added to the probe light path, setting the angle between the polarization directions of the pump light and the probe light to 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, thereby changing the relative time delay between the pump light and the probe light, thus obtaining the dynamics of transient spectral evolution and ensuring the accuracy and reliability of the data.

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

[0105] In some optional embodiments, the transient absorption measurement further includes nanosecond-resolved transient absorption measurement, which generates a first signal and a second signal through a delay signal generator DG645, and uses the delayed signal in the first signal and the second signal as the trigger signal of the nanosecond laser to achieve nanosecond resolution.

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

[0107] Step 206: After processing and comparing the two-dimensional spectral data of each group, the comparison results of carrier dynamics of the halogenated non-fullerene organic photovoltaic system are generated.

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

[0109] In some alternative embodiments, such as Figure 6 As shown, Figure 6 A flowchart of steps for generating alignment results provided in this application embodiment includes:

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

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

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

[0113] Step 608: Based on the transient absorption signal, the preset steady-state absorption signal, and the intermediate state absorption signal, compare the proportion of nonradiative charge recombination in different systems to obtain the comparison results of the carrier dynamics of the halogenated nonfullerene organic photovoltaic system.

[0114] The unexcited signal may include ambient light signal and interference signal. For example, the preset number can be 10, so that the average value of ten data points can be collected in advance as the unexcited signal.

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

[0116]

[0117] Where ε, l, and c are the molar absorption coefficient, the thickness of the comparison test sample, and the concentration of the comparison test sample, respectively; ε′ and c′ are the molar absorption coefficient and concentration after pump light excitation, respectively; ΔT is the difference in transmittance of the comparison test sample under pump light excitation and without pump light excitation in the transient absorption measurement experiment; T is the transmittance of the comparison test sample without pump light excitation in the transient absorption measurement experiment; λ is the wavelength of the probe light; t is time; and i is the increment of time.

[0118] This application also provides a specific process for conducting multiple sets of comparative test samples and subsequent experiments. The polymer donor PM6, PBDB-T, and organic small molecule acceptors Y5, Y6, and Y7 are independently dissolved in chloroform solvent at a concentration of 16 mg / mL, which is the highest concentration for photovoltaic active layer efficiency. The solutions are stirred overnight at room temperature in a glove box. PM6 and PBDB-T are then blended with the Y5, Y6, and Y7 solutions at a 1:2 ratio to prepare PBDB-T:Y5, PM6:Y6, and PM6:Y7 blend solutions, ensuring that the concentration of all blend solutions is 16 mg / mL. Before spin coating, the blend solutions are stirred at a constant temperature of 35°C for 2 hours. The organic mixture is then spin-coated onto a cleaned and dried 1 mm thick quartz substrate in an argon-atmosphere glove box. The spin coater is set to a speed of 3000 rpm for 60 seconds. The freshly prepared blended membranes were immediately annealed at 110℃ for 10 minutes. Then, PM6, PBDB-T, and Y5, Y6, Y7 pure membranes were prepared using the same concentration and procedure, resulting in three sets of comparative test samples. PtOEP was used as a triplet sensitizer, and triplet sensitized samples with a concentration of 16 mg / mL were prepared by dissolving PtOEP in chloroform solvent at a mass ratio of 1:4 for Y5, Y6, and Y7. All samples were kept to a relatively uniform thickness, and their surfaces were clean, flat, and free of scratches and contaminants to ensure that subsequent pump light excitation of the samples did not generate scattering and diffraction interference signals unrelated to photoelectric conversion kinetics.

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

[0120] When generating pump and probe light using an ultrafast transient absorption spectroscopy system, a regenerative amplifier with a center wavelength of 800 nm and a repetition frequency of 5 kHz outputs femtosecond pulses. The polarization direction is first adjusted to perpendicular using a lifting and redirection method, and then split into two beams by a 1:9 beam splitter. The stronger beam, after passing through a delay line, is frequency-doubled to 400 nm using a barium borate (BBO) crystal. The remaining 800 nm fundamental frequency light is filtered out, and the 400 nm beam is then focused onto a parametric amplification BBO crystal using a lens. The BBO crystal is positioned 1-2 cm behind the focal point of the 400 nm pump light to avoid damage. The weaker 800 nm beam, after passing through a variable attenuator and an aperture, is focused onto a 1.5 mm sapphire crystal using a lens to generate supercontinuous white light, which serves as the signal light to be amplified.

[0121] Next, the generated supercontinuous white light passes through a Schottky glass filter and is then incident on a BBO crystal at a specific angle using a concave mirror. When the pump light and signal light coincide in both time and space, a broadband output pulse is generated. Since the BBO crystal spontaneously emits superfluorescence in its phase-matching direction under pump light illumination, the phase-matching direction of the BBO crystal is first adjusted to focus all wavelengths of superfluorescence together as much as possible, resulting in the thinnest superfluorescence ring. Then, the signal light is coupled to the direction of superfluorescence radiation, automatically satisfying the ultra-broadband phase-matching condition. Fine-tuning the temporal and spatial coincidence yields a pump light of a specific wavelength. Because it passes through many dispersive media such as filters, the newly amplified signal light pulse has a large group delay dispersion. Due to this group delay dispersion, it must be compressed to output an ultrashort pulse.

[0122] Optionally, in this experiment, a chirped mirror pair method can be used to compress the pulse. A chirped mirror is a specially designed one-dimensional photonic crystal that allows long-wavelength light to be reflected deeper into the mirror surface while short-wavelength light is reflected shallower. This results in a longer optical path for long-wavelength light during reflection, thus introducing negative group velocity dispersion. Compression is achieved by simply reflecting the parametrically amplified pulse back and forth between the chirped mirror pairs several times. Since the negative dispersion introduced by each reflection between the chirped mirror pairs is a fixed value, a set of adjustable-insertion optical wedges is typically used after the chirped mirror pairs to continuously adjust the compression amount. Next, the pump light is further collimated and incident on the delay line to ensure that the optical path remains stable and does not shift when the delay line is adjusted. The pump light is passed through a chopper with a frequency half that of the emitted laser to control the spectrometer to determine whether the pump light passes through, thus achieving data acquisition cycles. After passing through a polarizer and adjusting the polarization, the light is then incident on the nitrogen atmosphere sample stage.

[0123] The second beam is split into two paths using a flip-up mirror mount: a visible detection path and a near-infrared detection path. Within the visible path, the second 800nm ​​fundamental frequency beam is split into three beams by a beam splitter. One beam generates a seed beam through a YAG crystal, another pumps the first-stage OPA, and the last pumps the second-stage OPA. Spatial and temporal coincidence are adjusted to generate amplified light with a wavelength of approximately 4 μJ at 1300nm during first-stage amplification and approximately 24 μJ during second-stage amplification. The amplified 1300nm light is further collimated and focused to generate a 500-950nm wide-spectrum supercontinuum white light on the sapphire crystal, which serves as the probe beam. This light is then compressed by a chirped mirror and filtered and adjusted for intensity using an aperture and filter. Finally, it is focused onto the sample stage using convex and concave lenses. When the mirror frame is flipped, the second beam of light passes through the lens and aperture before incident on the YAG crystal, generating a 950-1600nm near-infrared supercontinuous white light. This white light is then filtered and focused by the lens to serve as the probe light. The probe light is split into two beams by a beam splitter: a signal beam and a reference beam. As time changes, the white light remains unaffected by the pump light. The reference beam is used as the reference intensity, thereby eliminating the influence of environmental noise and improving measurement accuracy.

[0124] This application also provides a schematic diagram of the data processing results for three sets of comparative test samples PBDB-T:Y5, PM6:Y6, and PM6:Y7, as shown below. Figures 8-12 As shown, Figure 8 This is a schematic diagram comparing the transient spectra of a Y5 triplet sensitized sample obtained by sensitization with that of a comparison test sample at 1500 ps, ​​provided in an embodiment of this application. The Y5 triplet sensitized sample is Y5:PtOEP, and T = 1500 ps indicates a time delay of 1500 ps. Figure 9 This is a schematic diagram of the transient absorption kinetics of a power-dependent PBDB-T:Y5 comparison test sample provided in an embodiment of this application, where T = 1000ps indicates a time delay of 1000ps. Figure 10 This is a schematic diagram of the transient absorption spectra of three sets of comparative test samples, PBDB-T:Y5, PM6:Y6 and PM6:Y7, with a time delay of 1ns, provided for an embodiment of this application. T = 1000ps indicates that the time delay is 1000ps, which is 1ns. Figure 11 This is a schematic diagram of picosecond time-resolved dynamics curves of three sets of comparative test samples at 1450 nm, provided as an embodiment of this application. Figure 12 This is a schematic diagram of nanosecond time-resolved dynamics curves at 940 nm and 1150 nm for three sets of comparative test samples provided in an embodiment of this application. The above... Figures 8-12 The data represented on the vertical axis are all normalized differential rates of change of transmittance. Δ T / T).

[0125] Steady-state absorption spectra of all comparison test samples and triplet-sensitized samples were measured. Two-dimensional spectral data were obtained by exciting the donor and acceptor of the comparison test samples with pump light at wavelengths of 540 nm and 730 nm and a power density of 3.2 μJ / cm². Ten data points were pre-collected as unexcited signals before the equal optical path point measurement. After averaging, this average value was subtracted from the overall spectral data. The transient spectra of the excited state signals (such as those at 940 nm and 1450 nm) at different time delays were then extracted from the remaining two-dimensional spectral data and compared with the steady-state absorption signals to determine the intermediate state signals.

[0126] It can be seen that the excited-state absorption signal at 940 nm is correspondingly enhanced. This excited-state absorption signal generated at 940 nm cannot be observed in the monomeric pure membranes of the acceptor and donor, and it coexists with the ground-state bleaching signals of the donor and acceptor. Therefore, this can be considered an interfacial charge-transfer state. After the interfacial charge transfer, a slight redshift occurs on a timescale of 30–200 ps, ​​indicating that the interfacial charge-transfer state undergoes further charge separation to form free charges, and after decaying for 1 ns, an excited-state absorption signal appears at 1450 nm.

[0127] Please continue to refer to this. Figure 9 By comparing transient absorption measurements of the test samples at gradient power densities of 1, 2, 4, 8, and 16 μJ / cm², and normalizing the data to the ground-state bleaching signal generated at 940 nm, the power dependence of the signal at 1450 nm was obtained. At higher pump power densities, the spectral signal characteristics at 1450 nm were more pronounced, suggesting this signal process is a non-radiative recombination process. Then, the triplet-sensitized sample was subjected to the same pump detection to obtain its two-dimensional spectral data. Data from the same unsensitized and sensitized samples at a delay of 1 ns were extracted, and after normalization, the characteristics at 1450 nm matched, indicating a triplet-state signal.

[0128] The 1450nm signal at 1ns for all three sets of comparative test samples was extracted. The signal intensity of the charge splitting intermediate state at 940nm for each comparative test sample was normalized to eliminate the influence of different comparative test samples on the different charge splitting efficiency of the pump light response. The signal was normalized again at 1ns where the signal appears, and the triplet signal characteristics were compared. The differential rate of change of the normalized transmittance was then used to determine the signal intensity. Δ The proportion of triplet states in the process is determined by T / T.

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

[0130] The method for measuring carrier dynamics in halogenated non-fullerene organic photovoltaic systems provided in this embodiment includes: acquiring multiple sets of comparative test samples; for each set of comparative test samples, controlling a pre-built ultrafast transient absorption spectroscopy system to measure the spectral dynamic changes of the comparative test samples under preset excitation conditions to obtain two-dimensional spectral data; and after data processing and comparative analysis of each set of two-dimensional spectral data, generating comparative results of carrier dynamics in halogenated non-fullerene organic photovoltaic systems. This scheme, by combining ultrafast transient absorption spectroscopy technology to measure carrier recombination dynamics in halogenated non-fullerene organic photovoltaic systems, can realize the measurement and data analysis of non-radiative recombination dynamics of different halogenated organic systems. Furthermore, the pump-probe technology is used to further improve the flexibility and accuracy of the measurement. In addition, the transient absorption spectroscopy system can be adjusted by mechanical delay lines and combined with a delay signal generator to achieve the required time domain resolution, providing dynamic information on picosecond and nanosecond time scales, which is convenient for studying the organic photoelectric conversion process.

[0131] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0132] This application also provides a device for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system, characterized in that the device includes 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:

[0133] An ultrafast transient absorption spectroscopy system is used to acquire multiple sets of comparative test samples; for each set of comparative test samples, the spectral dynamics changes of the comparative test samples under preset excitation conditions are measured to obtain two-dimensional spectral data, and the two-dimensional spectral data is sent to a computer device;

[0134] Computer equipment is used to acquire each set of two-dimensional spectral data, and after processing and comparing the data, generate comparison results of carrier dynamics of halogenated non-fullerene organic photovoltaic systems.

[0135] For details regarding the apparatus in the above embodiments and its beneficial effects, please refer to the detailed description of the above method embodiments, which will not be repeated here.

[0136] In one embodiment of this application, a computer device is provided, the computer device including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0137] Obtain multiple sets of comparative test samples;

[0138] For each group of comparative test samples, a pre-built ultrafast transient absorption spectroscopy system was controlled to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions, and two-dimensional spectral data were obtained.

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

[0140] In one embodiment of this application, the processor further performs the following steps when executing the computer program:

[0141] The pump light path module is controlled to generate pump light, so as to excite the test sample by pump light comparison;

[0142] The detection optical path module generates detection light to measure and compare the spectral dynamics changes of the test sample under preset excitation conditions, thereby obtaining two-dimensional spectral data. The preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity.

[0143] The control data acquisition module collects two-dimensional spectral data and sends the two-dimensional spectral data to a computer device for processing.

[0144] In one embodiment of this application, the processor further performs the following steps when executing the computer program:

[0145] The regenerative amplifier in the ultrafast transient absorption spectroscopy system is controlled to output 100 femtosecond pulses of light; wherein the center wavelength of the regenerative amplifier is 800 nm and the repetition frequency is 5 kHz;

[0146] A beam splitter at the output of a regenerative amplifier is used to split the femtosecond pulse light to obtain a first beam and a second beam; wherein the light intensity of the first beam is greater than that of the second beam.

[0147] The first beam is controlled to generate pump light through a first nonlinear optical crystal in the pump optical path module; the first nonlinear optical crystal includes a barium metaborate crystal.

[0148] The second beam is controlled to be focused onto the second nonlinear optical crystal by a flip mirror and a lens in the probe optical path module. The probe light is generated in the second nonlinear optical crystal through a variety of nonlinear processes. The probe light includes a signal light and a reference light. The reference light is not affected by the pump light. The second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanate phosphate crystal, and a sapphire crystal.

[0149] In one embodiment of this application, the processor further performs the following steps when executing the computer program:

[0150] For pump light under various preset excitation conditions, both the probe light and the pump light are controlled to hit the comparison test sample. The signal light in the probe light and the pump light are controlled to coincide on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, and the probe light after passing through the comparison test sample is obtained.

[0151] The probe light transmitted through the 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 this application, the processor further performs the following steps when executing the computer program:

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

[0154] After removing the unexcited signal from the two-dimensional spectral data, transient absorption measurements were performed. The differential rate of change of the transmittance of the comparative test sample to the probe light under pump light excitation and without pump light excitation was calculated, and the differential rate of change of transmittance was used as the transient absorption signal.

[0155] The transient absorption signal is compared with the preset steady-state absorption signal under a preset band and a preset time delay to determine the intermediate state absorption signal;

[0156] Based on transient absorption signals, preset steady-state absorption signals, and intermediate-state absorption signals, the comparison results of the carrier dynamics of halogenated non-fullerene organic photovoltaic systems are obtained by comparing the proportion of non-radiative charge recombination in different systems.

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

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

[0159] The computer device provided in this application embodiment has a similar implementation principle and technical effect to the above method embodiment, and will not be described again here.

[0160] In one embodiment of this application, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, it performs the following steps:

[0161] Obtain multiple sets of comparative test samples;

[0162] For each group of comparative test samples, a pre-built ultrafast transient absorption spectroscopy system was controlled to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions, and two-dimensional spectral data were obtained.

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

[0164] In one embodiment of this application, the computer program, when executed by a processor, further performs the following steps:

[0165] The pump light path module is controlled to generate pump light, so as to excite the test sample by pump light comparison;

[0166] The detection optical path module generates detection light to measure and compare the spectral dynamics changes of the test sample under preset excitation conditions, thereby obtaining two-dimensional spectral data. The preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity.

[0167] The control data acquisition module collects two-dimensional spectral data and sends the two-dimensional spectral data to a computer device for processing.

[0168] In one embodiment of this application, the computer program, when executed by a processor, further performs the following steps:

[0169] The regenerative amplifier in the ultrafast transient absorption spectroscopy system is controlled to output 100 femtosecond pulses of light; wherein the center wavelength of the regenerative amplifier is 800 nm and the repetition frequency is 5 kHz;

[0170] A beam splitter at the output of a regenerative amplifier is used to split the femtosecond pulse light to obtain a first beam and a second beam; wherein the light intensity of the first beam is greater than that of the second beam.

[0171] The first beam is controlled to generate pump light through a first nonlinear optical crystal in the pump optical path module; the first nonlinear optical crystal includes a barium metaborate crystal.

[0172] The second beam is controlled to be focused onto the second nonlinear optical crystal by a flip mirror and a lens in the probe optical path module. The probe light is generated in the second nonlinear optical crystal through a variety of nonlinear processes. The probe light includes a signal light and a reference light. The reference light is not affected by the pump light. The second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanate phosphate crystal, and a sapphire crystal.

[0173] In one embodiment of this application, the computer program, when executed by a processor, further performs the following steps:

[0174] For pump light under various preset excitation conditions, both the probe light and the pump light are controlled to hit the comparison test sample. The signal light in the probe light and the pump light are controlled to coincide on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, and the probe light after passing through the comparison test sample is obtained.

[0175] The probe light transmitted through the 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 this application, the computer program, when executed by a processor, further performs the following steps:

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

[0178] After removing the unexcited signal from the two-dimensional spectral data, transient absorption measurements were performed. The differential rate of change of the transmittance of the comparative test sample to the probe light under pump light excitation and without pump light excitation was calculated, and the differential rate of change of transmittance was used as the transient absorption signal.

[0179] The transient absorption signal is compared with the preset steady-state absorption signal under a preset band and a preset time delay to determine the intermediate state absorption signal;

[0180] Based on transient absorption signals, preset steady-state absorption signals, and intermediate-state absorption signals, the comparison results of the carrier dynamics of halogenated non-fullerene organic photovoltaic systems are obtained by comparing the proportion of non-radiative charge recombination in different systems.

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

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

[0183] The computer-readable storage medium provided in this embodiment is similar in principle and technical effect to the method embodiment described above, and will not be repeated here.

[0184] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0185] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0186] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for measuring carrier dynamics in a halometallic nonfullerene organic photovoltaic system, characterized in that, The method includes: Obtain multiple sets of comparative test samples; The ultrafast transient absorption spectroscopy system includes a pump optical path module, a probe optical path module, and a data acquisition module. For each group of comparative test samples, the pre-built ultrafast transient absorption spectroscopy system is controlled to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions, obtaining two-dimensional spectral data. This includes: controlling the pump optical path module to generate pump light to excite the comparative test samples; controlling the probe optical path module to generate probe light to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions, obtaining two-dimensional spectral data; wherein the preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity; controlling the data acquisition module to acquire the two-dimensional spectral data and sending it to a computer for processing; and measuring the spectral dynamics changes of the comparative test samples under preset excitation conditions using the probe light. The method describes the spectral dynamics changes of the comparison test sample under preset excitation conditions to obtain two-dimensional spectral data, including: for pump light under each preset excitation condition, controlling both the probe light and the pump light to strike the comparison test sample, and controlling the signal light in the probe light to coincide with the pump light on the surface of the comparison test sample, blocking the pump light after passing through the comparison test sample to obtain the probe light after passing through the comparison test sample; controlling the probe light after passing through the comparison test sample to be transmitted to the spectrometer in the ultrafast transient absorption spectroscopy system to obtain the two-dimensional spectral data; wherein, the comparison test sample is measured in a nitrogen atmosphere, and a half-wave plate is added to the probe light path, setting the angle between the polarization direction of the pump light and the polarization direction of the probe light to a magic angle of 54.7°; and using a mechanical delay line or a delay signal generator to change the relative time delay between the pump light and the probe light; After processing and comparing the two-dimensional spectral data of each group, the comparison results of the carrier dynamics of the halide non-fullerene organic photovoltaic system are generated.

2. The method according to claim 1, characterized in that, The method further includes: The regenerative amplifier in the ultrafast transient absorption spectroscopy system is controlled to output 100 femtosecond pulses of light; wherein the center wavelength of the regenerative amplifier is 800 nm and the repetition frequency is 5 kHz. The beam splitter at the output of the regenerative amplifier is controlled to split the femtosecond pulse light to obtain a first beam and a second beam; wherein the light intensity of the first beam is greater than that of the second beam. The first beam is controlled to generate the pump light through a first nonlinear optical crystal in the pump optical path module; The first nonlinear optical crystal includes a barium metaborate crystal; The second beam is controlled to be focused onto a second nonlinear optical crystal by a flip mirror and a lens in the detection optical path module. The detection light is generated in the second nonlinear optical crystal through a variety of nonlinear processes. The detection light includes a signal light and a reference light. The reference light is not affected by the pump light. The second nonlinear optical crystal includes a yttrium aluminum garnet crystal, a potassium titanate phosphate crystal, and a sapphire crystal.

3. The method according to claim 1 or 2, characterized in that, After processing and comparing the two-dimensional spectral data of each group, the comparison results of the carrier dynamics of the halide non-fullerene organic photovoltaic system are generated, including: For each group of two-dimensional spectral data, the average value corresponding to a preset number of data points is obtained, and the average value is used as the unexcited signal; wherein, the unexcited signal includes ambient light signal and interference signal; After removing the unexcited signal from the two-dimensional spectral data, transient absorption measurement is performed. The differential rate of change of the transmittance of the comparative test sample to the probe light under pump light excitation and pump light excitation is calculated, and the differential rate of change of the transmittance is used as the transient absorption signal. The transient absorption signal is compared with the preset steady-state absorption signal under a preset band and a preset time delay to determine the intermediate state absorption signal; Based on the transient absorption signal, the preset steady-state absorption signal, and the intermediate state absorption signal, the ratio of nonradiative charge recombination in different systems is compared to obtain the comparison results of the carrier dynamics of the halide nonfullerene organic photovoltaic system.

4. The method according to claim 3, characterized in that, The transient absorption measurement includes picosecond-resolution transient absorption measurement, which utilizes a mechanical delay line for optical path delay and can achieve picosecond resolution.

5. The method according to claim 3, 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 delay signal generator, and uses the delayed signal in the first signal and the second signal as the trigger signal of the nanosecond laser to achieve nanosecond resolution.

6. A device for measuring carrier dynamics in a halogenated non-fullerene organic photovoltaic system, characterized in that, The device includes an ultrafast transient absorption spectroscopy system and a computer device, which are communicatively connected. The ultrafast transient absorption spectroscopy system is used to acquire multiple sets of comparative test samples. For each set of comparative test samples, the system measures the spectral dynamics changes of the comparative test samples under preset excitation conditions to obtain two-dimensional spectral data. This includes: controlling a pump optical path module to generate pump light to excite the comparative test samples; controlling a probe optical path module to generate probe light to measure the spectral dynamics changes of the comparative test samples under preset excitation conditions to obtain two-dimensional spectral data; wherein the preset excitation conditions are determined based on the pump light wavelength, excitation position, and excitation intensity; controlling a data acquisition module to acquire the two-dimensional spectral data and sending it to the computer device for processing; and measuring the spectral dynamics changes of the comparative test samples under preset excitation conditions using the probe light. The method involves measuring the spectral dynamics changes of the comparison test sample under preset excitation conditions to obtain two-dimensional spectral data. This includes: for each preset excitation condition, controlling both the probe light and the pump light to strike the comparison test sample, and controlling the signal light in the probe light to coincide with the pump light on the surface of the comparison test sample. After passing through the comparison test sample, the pump light is blocked, resulting in probe light that has passed through the comparison test sample. The probe light that has passed through the comparison test sample is then transmitted to a spectrometer in an ultrafast transient absorption spectroscopy system to obtain the two-dimensional spectral data. The comparison test sample is measured in a nitrogen atmosphere, and a half-wave plate is added to the probe light path, setting the angle between the polarization directions of the pump light and the probe light to a magic angle of 54.7°. A mechanical delay line or a delay signal generator is used to change the relative time delay between the pump light and the probe light. Finally, the two-dimensional spectral data is sent to a computer. The computer device is used to acquire the two-dimensional spectral data of each group, and after processing and comparing the two-dimensional spectral data of each group, generate the comparison results of the carrier dynamics of the halogenated non-fullerene organic photovoltaic system.

7. An electronic device, characterized in that, The electronic device includes a processor and a memory, the memory storing at least one instruction, at least one program, a code set, or an instruction set, the at least one instruction, the at least one program, the code set, or the instruction set being loaded and executed by the processor to implement the steps of the method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The storage medium stores at least one instruction, at least one program, code set, or instruction set, wherein 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 steps of the method as described in any one of claims 1-5.

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