Transient photovoltage test system and method with spatial resolution

Abstract

The invention relates to a transient photovoltage test system and method with spatial resolution, and belongs to the technical field of semiconductors. The transient photovoltage test system comprises a first light source device which is used for applying pulse light excitation of different wavelengths to a device to be tested and forming photogenerated voltages of different depths on the device to be tested; the second light source device comprises a condensation system and a steady-state light source; the light condensing system is placed below the first light source device and is used for adjusting the intensity of pulsed light emitted by the first light source device and acting on the device to be detected and the size of a light spot; the steady-state light source is used for irradiating the to-be-tested device to provide light modulation, so that stable charge distribution with adjustable concentration is established in the to-be-tested device; the voltage detection device is used for detecting photo-generated voltage in real time; and the imaging device is used for displaying the position of the pulsed light on the to-be-measured device. According to the invention, to-be-measured devices with different depths and different micro-regions can be measured, and the characterization of the three-dimensional space resolution charge recombination characteristic of the semiconductor device is realized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a spatially resolved transient photovoltage testing system and method. Background Art

[0002] With the continuous in-depth research of semiconductor technology and solar cell research, exploring the optoelectronic processes inside semiconductor devices such as solar cells is extremely crucial for understanding their working principles and improving efficiency. The optoelectronic processes of solar cells mainly involve the generation, transport, collection, and recombination of photo-generated charges. Among them, the recombination process directly affects the current output and photo-generated voltage of the device, and thus determines the structure and performance of the device. Therefore, accurately measuring and analyzing the recombination process of photo-generated charges is of great significance for the research of solar cells and related devices.

[0003] Currently, the main methods for studying the photo-generated charge recombination process of solar cells are electrochemical impedance spectroscopy and transient photovoltage. Electrochemical impedance spectroscopy can study the AC response of the device in a wide frequency range, but when analyzing the recombination characteristics, it relies on a complex device model, and the accuracy of model selection will directly affect the analysis results, resulting in difficulty in directly obtaining recombination process information.

[0004] In contrast, the transient photovoltage method can directly reflect the decay process of the photovoltage generated by photo-generated non-equilibrium charges. This process directly corresponds to the recombination of photo-generated charges and can relatively directly obtain key parameters such as recombination lifetime and rate. Therefore, it has more advantages in studying charge recombination. Although the transient photovoltage method has been applied to a certain extent in related fields, traditional transient photovoltage testing systems still have some limitations. Specifically, these traditional systems cannot achieve precise measurement of local regions, different depths, and micro-regions of semiconductor devices, thus limiting the in-depth study of the internal microscopic charge recombination characteristics of the devices. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the inability to measure different depths and different micro-regions of semiconductor devices in the prior art.

[0006] In a first aspect, to solve the above technical problem, the present invention provides a spatially resolved transient photovoltage testing system, including:

[0007] A first light source device for applying pulsed light excitation of different wavelengths to the device under test and forming photovoltages of different depths on the device under test;

[0008] The second light source device includes a condensing system and a steady-state light source; the condensing system is placed below the first light source device and is used to adjust the intensity and spot size of the pulsed light emitted by the first light source device acting on the device under test; the steady-state light source is used to irradiate the device under test to provide optical modulation, so as to establish a charge distribution with adjustable concentration stably existing inside the device under test;

[0009] A voltage detection device is used to detect the photo-generated voltage in real time;

[0010] An imaging device is used to display the position of the pulsed light on the device under test.

[0011] In an embodiment of the present invention, the voltage detection device includes a digital oscilloscope and a sampling resistor connected in parallel, wherein the sampling resistor is connected in series with the device under test to form a voltage detection loop.

[0012] In an embodiment of the present invention, the first light source device includes a plurality of lasers, and each of the lasers is connected through transistor-transistor logic modulation.

[0013] In an embodiment of the present invention, the condensing system includes a condenser lens, a diaphragm, and a beam splitter disposed between the pulsed light source and the device under test.

[0014] In an embodiment of the present invention, the pulsed light source emitted by the first light source device has a narrow pulse width and a long pulse period and the wavelength of the pulsed light source is adjustable.

[0015] In an embodiment of the present invention, it further includes a sample stage connected to the device under test; the sample stage is movable and is used to adjust the spot position of the pulsed light on the device under test.

[0016] In an embodiment of the present invention, it further includes a sample chamber for accommodating the device under test and providing a predetermined test environment for the device under test.

[0017] In an embodiment of the present invention, the imaging device includes an industrial camera, a computer, and a display screen; the industrial camera is used to acquire the position picture of the pulsed light on the device under test in real time; the computer is used to receive and process the position picture in real time; the display screen is used to display the processed position picture in real time.

[0018] In a second aspect, to solve the above technical problems, the present invention provides a transient opto-voltage testing method with spatial resolution, including:

[0019] Modulating the irradiation light of the device under test and establishing a charge distribution with adjustable concentration stably existing inside the device under test;

[0020] When the charge distribution tends to be stable, pulsed light of different wavelengths is applied to the device under test to generate photo-generated charges on the device under test; the photo-generated charges accumulate on both sides of the device under test to form photo-generated voltages of different depths.

[0021] Adjust the intensity and spot size of the pulsed light acting on the device under test, detect the photo-generated voltage in different states in real time, and display the position of the pulsed light on the device under test in real time.

[0022] In a third aspect, to solve the above technical problems, the present invention provides a transient optoelectronic measuring instrument, including the above-mentioned transient opto-voltage test system with spatial resolution.

[0023] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0024] (1) In the transient opto-voltage test system and method with spatial resolution of the present invention, photo-generated charges inside the device under test are excited by the first light source device. At the same time, the irradiation light is modulated by the second light source device, and a stable and adjustable-concentration charge distribution can be constructed inside the device under test. This stable background charge distribution provides a reliable reference benchmark for subsequent measurements, making the generation and recombination processes of photo-generated charges clearer and easier to measure. In addition, the voltage detection device is used to detect and record the photo-generated voltage formed by the photo-generated charges in real time, so as to characterize the charge recombination property of the device under test.

[0025] (2) The present invention not only realizes the characterization of the charge recombination properties of the device under test at different depths and different micro-regions, but also realizes the three-dimensional spatial resolution characterization of the charge recombination characteristics of semiconductor devices. Description of the Drawings

[0026] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to the specific embodiments of the present invention and in conjunction with the drawings, where:

[0027] Figure 1 is a schematic structural diagram of a transient opto-voltage test system with spatial resolution in a preferred embodiment of the present invention;

[0028] Figure 2 is a structural diagram of a condenser system in a preferred embodiment of the present invention;

[0029] Figure 3 is a graph showing the change of the photo-generated voltage with time at the amplitude of the same photo-voltage under different wavelength pulsed light sources detected for a TOPCon solar cell in a preferred embodiment of the present invention;

[0030] Figure 4Box plot of the photovoltage lifetime and wavelength of the front side of the TOPCon solar cell detected in the preferred embodiment of the present invention under pulsed light sources of different wavelengths with the same photovoltage amplitude;

[0031] Figure 5 Box plot of the photovoltage lifetime and wavelength of the back side of the TOPCon solar cell detected in the preferred embodiment of the present invention under pulsed light sources of different wavelengths with the same photovoltage amplitude;

[0032] Figure 6 Flow chart of a transient photovoltage test method with spatial resolution in the preferred embodiment of the present invention.

[0033] Explanation of reference numerals in the drawings of the specification: 1. Semiconductor device; 2. Steady-state light source; 3. Pulsed light source; 4. Condensing system; 41. Convex lens; 42. Diaphragm; 43. Beam splitter; 5. Voltage detection device; 51. Sampling resistor; 52. Digital oscilloscope; 6. Imaging device; 7. Sample chamber. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited shall not be construed as limitations on the present invention.

[0035] Embodiment 1

[0036] Refer to Figure 1 As shown, the embodiment of the present invention provides a transient photovoltage test system with spatial resolution, including:

[0037] A first light source device for applying pulsed light excitation of different wavelengths to the device under test and forming photovoltages of different depths on the device under test;

[0038] A second light source device includes a condensing system 4 and a steady-state light source 2; the condensing system 4 is placed below the first light source device and is used to adjust the intensity and spot size of the pulsed light emitted by the first light source device acting on the device under test; the steady-state light source 2 is used to irradiate the device under test to provide optical modulation, so that a charge distribution with a stable and adjustable concentration is established inside the device under test;

[0039] A voltage detection device 5 for detecting the photovoltage in real time;

[0040] An imaging device 6 for displaying the position of the pulsed light on the device under test.

[0041] A transient opto - voltage test system with spatial resolution provided by an embodiment of the present invention can excite photo - generated charges inside a device under test through a first light source device, and accumulate them at both ends of the device under test to form a photo - generated voltage. The photo - generated voltage is detected and recorded in real time by a voltage detection device 5 to characterize the charge recombination property of the device under test. Meanwhile, the condenser system 4 of the embodiment of the present invention can adjust the intensity and spot size of the pulsed light, so that the pulsed light irradiates different micro - regions of the device under test, realizing the characterization of the charge recombination property of the device under test at different micro - regions, and further realizing the characterization of the internal spatial defect states of the device under test. In addition, by placing the condenser system below the first light source device and combining the use of a steady - state light source in the embodiment of the present invention, the complex circuit design requirements in the prior art are avoided, and the system also has a spatial resolution function that the prior art does not have, thus significantly improving the performance and practicality of the system.

[0042] Furthermore, in the embodiment of the present invention, the first light source device realizes the excitation of photo - generated charges at different depths of the device under test. Since light with different wavelengths has different penetration depths, the charge recombination characteristics of the device at different depths can be explored, thus realizing the resolution in the depth direction. At the same time, by adjusting the condenser system 4 to position the light spot at different positions on the plane of the device under test, the charge recombination characteristics of the device at different positions can be explored, realizing the resolution on the two - dimensional plane. Combining the resolution in the depth direction with the resolution on the two - dimensional plane, the embodiment of the present invention realizes the three - dimensional spatial resolution characterization of the charge recombination property of the device under test. This innovative method can not only provide detailed charge recombination information at different depths and positions inside the device, but also provide strong technical support for optimizing the device performance and understanding its working principle.

[0043] Specifically, in this embodiment, the device under test is a semiconductor device 1, such as a solar cell or a semiconductor PN junction. The first light source device includes a pulsed light source 3. The pulsed light source 3 applies pulsed light with different wavelengths to excite the semiconductor device 1, thereby forming photo - generated charges at different depths inside the semiconductor device 1. These photo - generated charges will accumulate on both sides of the semiconductor device 1, and then form a photo - generated voltage. It should be noted that pulsed lasers with different wavelengths have different penetration depths and can excite photo - generated charges at different depths inside the semiconductor device 1. Specifically, when pulsed lasers with different wavelengths irradiate the semiconductor device 1, their light intensity gradually attenuates as the distance into the semiconductor device 1 increases. The semiconductor device 1 has different absorption coefficients for light with different wavelengths, which determines the penetration depth of light in the semiconductor device 1. When the absorption coefficient is high, the light is absorbed near the surface of the semiconductor device 1, resulting in a rapid attenuation of the light intensity; while when the absorption coefficient is low, the light can penetrate deeper into the semiconductor device 1. The penetration depth is defined as the depth at which the light intensity attenuates to 1 / e of its initial light intensity.

[0044] Furthermore, multiple lasers with different wavelengths are customized in the pulsed light source 3, and each laser is connected through TTL (Transistor-Transistor Logic) modulation technology to achieve the effective generation of pulsed laser. TTL modulation precisely controls the switch state of the laser through the high and low level signals output by the TTL circuit. Specifically, when the TTL circuit outputs a high level, the laser is activated and the laser beam is emitted; on the contrary, when the TTL circuit outputs a low level, the laser is turned off and the laser beam stops emitting. This modulation method can not only precisely control the generation of laser, but also adjust the pulse characteristics of the laser according to different application requirements, so as to meet diverse scientific research and industrial applications.

[0045] Furthermore, in this embodiment, the pulsed light source 3 has a very narrow pulse width and a long pulse period, and its wavelength can be adjusted according to requirements. This design enables the pulsed light source 3 to accurately excite the photo-generated charges inside the device under test, providing strong support for accurately measuring the charge recombination characteristics. In this embodiment, the pulsed light source 3 is preferably a pulsed laser or a high-speed controlled LED lamp, and both of these light sources have high energy density and fast response capabilities, and can meet the requirements of the system for high time resolution and adjustable wavelength.

[0046] Specifically, the steady-state light source 2 irradiates the semiconductor device 1 to provide optical modulation, so as to establish a charge distribution with adjustable concentration that stably exists inside the semiconductor device 1. Specifically, the core function of the steady-state light source 2 is to provide a stable optical excitation environment for the device under test, so as to generate a charge distribution that stably exists inside the device. This stable background charge distribution can be used as a reference state, making the generation and recombination processes of photo-generated charges clearer and measurable during the subsequent pulsed light excitation process. By adjusting the intensity of the steady-state light source 2, the concentration of the background charge can be controlled, so as to study the charge recombination characteristics under different initial charge concentrations. The optical modulation provided by the steady-state light source 2 can enhance the sensitivity and accuracy of the measurement. By performing pulsed light excitation under a stable background charge distribution, the transient changes of photo-generated charges can be observed more clearly, so as to more accurately measure key parameters such as charge recombination lifetime and recombination rate. In addition, this stable background charge distribution can reduce the noise and interference during the measurement process and improve the reliability of the measurement results. In this embodiment, the steady-state light source 2 selected is an LED lamp with continuously adjustable intensity, which can make the semiconductor device 1 in different illumination states, so as to comprehensively characterize the photo-generated charge recombination properties of the semiconductor device 1 under different illumination conditions.

[0047] Specifically, the light condensing system 4 is used to adjust the intensity and spot size of the pulsed light received by the semiconductor device 1, ensuring that the pulsed light irradiates the semiconductor device 1 under suitable conditions. In this embodiment, the light condensing system 4 includes a condenser lens, a diaphragm 42, and a beam splitter 43 disposed between the pulsed light source 3 and the semiconductor device 1, as can be referred to Figure 2 as shown. Among them, the condenser lens includes a plurality of convex lenses 41, and these convex lenses 41 are arranged in sequence according to the incident direction of the light beam. Taking a condenser lens including three convex lenses 41 as an example, the first lens is responsible for initially converging the incident light rays, laying the foundation for subsequent focusing steps. Subsequently, the second convex lens continues this process, further enhancing the focusing effect of the light beam. After the light beam passing through the first two convex lenses, it will pass through the diaphragm 42. The main function of the diaphragm 42 is to adjust the diameter of the light beam, optimizing the quality and shape of the light beam. Immediately afterwards, the third convex lens performs the final fine adjustment on the light beam passing through the diaphragm. This step is crucial because it ensures that the light beam can irradiate the beam splitter 43 with extremely high precision, thereby achieving precise control and effective distribution of the light beam.

[0048] The light condensing system 4 focuses the pulsed light through the condenser lens, controls the diameter of the light beam using the diaphragm 42, and then the beam splitter 43 can distribute the light beam as needed. The three work together to achieve precise control of the pulsed light.

[0049] Specifically, the voltage detection device 5 forms a voltage detection circuit with the semiconductor device 1 and is used to detect the photo-generated voltage across the semiconductor device 1 in real time. The voltage detection device 5 has a time resolution on the picosecond or nanosecond scale. In this way, the continuous photo-generated voltages measured by the voltage detection device 5 within a continuous period of time can form a curve of the photo-generated voltage varying with time. In this embodiment, the voltage detection device 5 includes a digital oscilloscope 52 and a sampling resistor 51 connected in parallel. Among them, the sampling resistor 51 is connected in series with the semiconductor device 1 and is used to convert the photo-generated voltage into a measurable current signal, while the digital oscilloscope 52 is responsible for recording and analyzing these signals to ensure the accuracy and reliability of the measurement results.

[0050] Specifically, the imaging device 6 is used to display the position of the pulsed light source 3 on the semiconductor device 1. In this embodiment, the imaging device 6 includes an industrial camera, a computer, and a display screen. Among them, the industrial camera is used to obtain the position picture of the pulsed light on the device to be measured in real time; the computer is used to receive and process the position picture in real time; the display screen is used to display the processed position picture in real time.

[0051] Furthermore, the connection methods of the industrial camera, computer, and display screen are as follows: The industrial camera is connected to the computer through a suitable interface (such as USB, GigE, or Camera Link) to capture and transmit image data; the computer is then connected to the display screen through a video output interface (such as HDMI, DisplayPort, or VGA) to display the image in real time. In terms of software, the driver programs of the camera and acquisition card (if any) need to be installed, and parameters (such as exposure time and gain) are configured through the camera control software to ensure that the image is clear and transmitted to the display screen in real time for viewing and analysis.

[0052] Furthermore, the industrial camera can be of types such as high-speed cameras, scientific-grade CMOS cameras, infrared imaging cameras, etc. In this embodiment, the industrial CCD camera is preferably selected. The industrial CCD camera has high sensitivity and can capture weak light signals, ensuring the imaging quality under low-light conditions. At the same time, its low-noise characteristic guarantees the clarity and accuracy of the image, which is crucial for occasions requiring high-precision measurement and analysis. In addition, the high dynamic range of the industrial CCD camera enables it to capture both bright and dark details in the image, which is particularly critical for imaging under complex lighting conditions. These characteristics make the industrial CCD camera perform excellently in imaging applications that require high resolution, high sensitivity, and low noise, and can provide accurate spot position and size information for the transient optical voltage test system, thus ensuring the accuracy and reliability of the test.

[0053] Furthermore, exemplary steps for the connection method of the imaging device 6 are given as follows: First, use a USB cable to connect the industrial CCD camera to the USB port of the computer, ensuring a secure connection to prevent loosening. Then, install the driver program of the industrial CCD camera to ensure that the computer can recognize and operate the camera normally. Subsequently, start the camera control software, complete the connection of the camera, and carefully configure relevant parameters (such as exposure time, gain, etc.) according to actual needs. In the software interface, turn on the real-time preview function to view and confirm the clarity and integrity of the image in real time. In addition, connect the computer to the display screen through an HDMI cable and make appropriate adjustments to the display settings as needed to ensure that the image can be presented in the best effect. Through the above steps, it can be ensured that the industrial CCD camera, computer, and display screen are correctly and efficiently connected and configured, thus guaranteeing the stable transmission of image data and real-time, clear display effects.

[0054] Specifically, the transient opto - voltage test system provided by the embodiments of the present invention is also equipped with a sample chamber 7 specifically for accommodating the semiconductor device 1. The sample chamber 7 has the ability to regulate the multi - functional environment, aiming to create a preset test environment for the semiconductor device 1, such as temperature environment, atmosphere environment, electromagnetic shielding and other conditions, so as to ensure that the test process is carried out in a highly controllable and stable environment, effectively avoiding the interference of external factors on the test results. On this basis, an industrial camera is placed inside the sample chamber 7. In this way, not only can the position of the pulsed light on the semiconductor device 1 be displayed, but also the experimental state inside the sample chamber 7 can be monitored in real time, further improving the overall performance and reliability of the test system.

[0055] Specifically, the transient opto - voltage test system is also equipped with a movable sample stage connected to the device under test. This sample stage can precisely adjust its position, so as to flexibly control the spot position of the pulsed light on the device under test. This design enables the system to measure in different regions of the device under test, further enhancing the spatial resolution ability of the system and providing strong support for comprehensively analyzing the charge recombination characteristics of the device.

[0056] Further, in order to more clearly elaborate the specific test process of the transient opto - voltage test system, the following takes the semiconductor device 1 as a TOPCon solar cell as an example for detailed description:

[0057] In this embodiment, the semiconductor device 1 is a TOPCon solar cell. The sampling resistor 51 is a high - impedance resistor with an impedance value of 1 MΩ. The positive and negative electrodes of the TOPCon solar cell are respectively led out and connected to both ends of the sampling resistor 51, and a digital oscilloscope 52 is used to detect and record the voltage across the sampling resistor 51 and its changes, thereby constructing a voltage detection circuit.

[0058] The steady - state light source is an LED lamp with continuously adjustable intensity, which irradiates the TOPCon solar cell. During this process, stable - distribution photo - generated charges with adjustable concentration are generated inside the solar cell, and a steady - state photo - generated current is formed. This steady - state photo - generated current can flow through the sampling resistor 51, and then the system is in an approximately open - circuit state.

[0059] At the same time, in this embodiment, the pulsed light source 3 is a pulsed laser, which irradiates the TOPCon solar cell to generate transient photo - generated charges. Under the action of the built - in electric field or diffusion inside the solar cell, these transient photo - generated charges will eventually accumulate at both ends of the cell, forming a photo - generated voltage. Subsequently, the accumulated transient photo - generated charges recombine at a certain speed inside the solar cell, resulting in a gradual decrease in the charge quantity and a corresponding decrease in the photo - voltage, thus presenting a dynamic process of the photo - voltage changing with time.

[0060] Through the transient opto - voltage test system constructed above, the curves of the opto - voltage varying with time of the TOPCon solar cell detected under different - wavelength pulsed light sources and under the condition of the same opto - voltage amplitude are as Figure 3 shown. Due to the good passivation contact characteristics between the layers of the TOPCon solar cell, the overall difference in the variation of the photo - generated voltage with time is not significant under the excitation of pulsed lasers with different wavelengths.

[0061] Furthermore, the box plot of the opto - voltage lifetime and wavelength of the TOPCon solar cell on the front side under different - wavelength pulsed light sources with the same photo - generated voltage amplitude is as Figure 4 shown. When irradiating from the front side, since there is a PN junction near the front - surface of the TOPCon solar cell, the recombination effect in this region is relatively significant, resulting in a shorter opto - voltage lifetime generated by the excitation of short - wavelength light (such as blue light and ultraviolet light). As the wavelength increases, the recombination influence near the PN junction gradually weakens, and the opto - voltage lifetime increases accordingly.

[0062] Furthermore, the box plot of the opto - voltage lifetime and wavelength of the TOPCon solar cell on the back side under different - wavelength pulsed light sources with the same photo - generated voltage amplitude is as Figure 5 shown. When irradiating from the back side, the Poly - Si layer on the back side will absorb short - wavelength lasers (such as 405 nm), so the opto - voltage lifetime under the 405 - nm pulsed laser cannot be measured. In addition, due to the good passivation effect of the TOPCon structure on the back side of the TOPCon solar cell, the recombination effect is small, resulting in a higher opto - voltage lifetime in the ultraviolet and visible light bands. However, when the wavelength increases to the infrared band, the laser can penetrate to near the PN junction on the front side of the cell, resulting in an enhanced recombination effect and a reduced opto - voltage lifetime.

[0063] From Figures 3 to 5 the test results, it can be concluded that light with different wavelengths has a significant and regular impact on the charge recombination characteristics of the TOPCon solar cell. This discovery not only strongly verifies the effectiveness and reliability of the transient opto - voltage test system described in the embodiments of the present invention in studying the internal charge recombination process of semiconductor devices 1, but also fully demonstrates the performance of this system in accurately characterizing charge recombination characteristics. Specifically, by using pulsed light sources, steady - state light sources 2, and a light - concentrating system 4 with different wavelengths, the present invention can accurately characterize the charge recombination characteristics of the TOPCon solar cell at different depths and different positions, thereby achieving three - dimensional spatial resolution of the internal charge recombination behavior of the device. This spatial resolution ability enables researchers to more comprehensively and deeply understand the internal working mechanism of the TOPCon solar cell, providing important technical support and theoretical basis for optimizing device performance and improving the photoelectric conversion efficiency.

[0064] Embodiment 2

[0065] Based on the same inventive concept, this embodiment provides a method for spatially resolved transient opto - voltage measurement. The principle of solving problems is similar to that of the spatially resolved transient opto - voltage measurement system provided in Embodiment 1, and the repeated parts will not be elaborated.

[0066] Refer to Figure 6 As shown, this embodiment provides a method for spatially resolved transient opto - voltage measurement, including but not limited to the following steps:

[0067] Modulate the irradiation light of the device under test and establish a charge distribution with adjustable concentration that stably exists inside the device under test;

[0068] When the charge distribution tends to be stable, apply pulsed light excitation with different wavelengths to the device under test and generate photo - generated charges on the device under test; the photo - generated charges accumulate on both sides of the device under test to form photo - generated voltages with different depths;

[0069] Adjust the intensity and spot size of the pulsed light acting on the device under test, detect the photo - generated voltage in different states in real time, and display the position of the pulsed light on the device under test in real time.

[0070] The method for spatially resolved transient opto - voltage measurement provided in this embodiment can construct a stable and concentration - adjustable charge distribution inside the device under test by modulating the irradiation light. This stable background charge distribution provides a reliable reference benchmark for subsequent measurements, making the generation and recombination processes of photo - generated charges clearer and easier to measure. At the same time, by using real - time detection technology to capture the transient changes of the photo - generated voltage in different states, this method can more accurately measure key parameters such as charge recombination lifetime and recombination rate, significantly improving the sensitivity and accuracy of the measurement. In addition, by flexibly adjusting the intensity and spot size of the pulsed light, this embodiment can control the generation position and quantity of photo - generated charges, so as to perform measurements under diverse conditions and more comprehensively explore the charge recombination characteristics of the device under test.

[0071] Embodiment 3

[0072] This embodiment provides a transient opto - electrical measuring instrument, including a spatially resolved transient opto - voltage measurement system provided in Embodiment 1.

[0073] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0074] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks or the combination of multiple flows and / or blocks.

[0075] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one or more of the flows Figure 1 or blocks or the combination of multiple flows and / or blocks.

[0076] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks or the combination of multiple flows and / or blocks.

[0077] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A transient optoelectronic voltage measurement system with spatial resolution, characterized in that Comprising: A first light source device for applying pulsed light excitation of different wavelengths to a device under test and generating photo-generated voltages of different depths on the device under test; A second light source device, including a condenser system and a steady-state light source; the condenser system is placed below the first light source device and is used to adjust the intensity and spot size of the pulsed light emitted by the first light source device acting on the device under test; The steady-state light source is used to irradiate the device under test to provide optical modulation, so as to establish a charge distribution with adjustable concentration stably existing inside the device under test; A voltage detection device for detecting the photo-generated voltage in real time; An imaging device for displaying the position of the pulsed light on the device under test.

2. The transient optoelectronic voltage measurement system with spatial resolution according to claim 1, wherein The voltage detection device includes a digital oscilloscope and a sampling resistor connected in parallel, wherein the sampling resistor is connected in series with the device under test to form a voltage detection loop.

3. The transient optoelectronic voltage testing system with spatial resolution according to claim 1, wherein The first light source device includes a plurality of lasers, and each laser is connected through transistor-transistor logic modulation.

4. A transient optoelectronic voltage measurement system with spatial resolution according to claim 1, characterized in that, The condenser system includes a condenser lens, a diaphragm and a beam splitter disposed between the pulsed light source and the device under test.

5. A transient opto-voltage test system with spatial resolution according to claim 1, wherein, The pulsed light source emitted by the first light source device has a narrow pulse width and a long pulse period and the wavelength of the pulsed light source is adjustable.

6. The transient optoelectronic voltage measurement system with spatial resolution according to claim 1, wherein It further includes a sample stage connected to the device under test; the sample stage is movable and is used to adjust the spot position of the pulsed light on the device under test.

7. A transient optoelectronic voltage measurement system with spatial resolution according to claim 1, wherein It further includes a sample chamber for accommodating the device under test and providing a predetermined test environment for the device under test.

8. A transient opto - voltage test system with spatial resolution according to claim 1, wherein ,The imaging device includes an industrial camera, a computer and a display screen; the industrial camera is used to acquire the position picture of the pulsed light on the device under test in real time; the computer is used to receive and process the position picture in real time; the display screen is used to display the processed position picture in real time.

9. A transient optoelectronic voltage testing method with spatial resolution, characterized in that, Comprising: Modulating the irradiation light of the device under test and establishing a charge distribution with adjustable concentration stably existing inside the device under test; When the charge distribution tends to be stable, applying pulsed light excitation of different wavelengths to the device under test and generating photo-generated charges on the device under test; the photo-generated charges accumulate on both sides of the device under test to form photo-generated voltages of different depths; Adjusting the intensity and spot size of the pulsed light acting on the device under test, detecting the photo-generated voltage in different states in real time, and displaying the position of the pulsed light on the device under test in real time.

10. A transient optoelectronic measuring instrument, characterized in that, Comprising a transient opto-voltage test system with spatial resolution according to any one of claims 1 to 8.

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