Non-destructive comprehensive measurement and evaluation method for spatial slave performance of multi-junction photovoltaic device

Abstract

This invention provides a non-destructive comprehensive measurement and evaluation method for the space-use performance of multi-junction photoelectric devices, comprising: detecting the optimal excitation wavelength of a selected PN junction based on the quantum transfer characteristics of the device; spatially irradiating the device based on the optimal excitation wavelength to detect the optimal fluorescence wavelength of the selected PN junction; periodically spatially irradiating the device based on the optimal fluorescence wavelength to diagnose the fluorescence decay relationship of the selected PN junction over time; diagnosing and determining the fluorescence lifetime of the selected PN junction based on the fluorescence decay relationship over time; replacing the selected PN junction and repeating the above steps until the fluorescence lifetimes of multiple PN junctions of the device are determined; combining the fluorescence lifetimes of multiple PN junctions, the current-voltage characteristics of the device, and the space irradiation type of the space-irradiated device to determine the normalized power decay curve of the device; and evaluating the cumulative total space irradiation, cumulative operating time, and predicting the remaining lifetime of the device based on the normalized power decay curve of the device.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices, and more particularly to a non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices and a performance evaluation system for multi-junction photoelectric devices. Background Technology

[0002] Photoelectric devices include solar cells, photodetectors, and other devices based on the mechanism of "photoelectricity generation." The basic working principle of photoelectric devices is as follows: when photons are projected onto the PN junction of the semiconductor material of the photoelectric device, electron-hole pairs are formed. Under the influence of the built-in electric field of the PN junction, the electron-hole pairs separate and move in a directional manner, forming an electric current. Therefore, solar cells and photodetectors can both be classified as photoelectric devices, and photoelectric devices have wide applications in the aerospace field.

[0003] However, when photoelectric devices are used in space environments, they are exposed to space radiation from atomic oxygen, electrons, and protons. The complex combination of these elements and prolonged space radiation can lead to performance degradation or even failure of the photoelectric devices.

[0004] Therefore, there is an urgent need in this field to establish a general, non-destructive, and effective method for comprehensive evaluation and prediction of the space service performance of devices, which can provide a basis and reference for the effective working life of key aerospace semiconductor devices. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0006] This invention provides a non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices. It can realize non-destructive testing of photoelectric devices and has wide applicability, simple operation and easy implementation.

[0007] Specifically, the non-destructive comprehensive measurement and evaluation method for the spatial performance of the multi-junction photoelectric device provided by the first aspect of the present invention includes: Step S1: Detecting the optimal excitation wavelength of a selected PN junction of the device based on the quantum transfer characteristics of the device; Step S2: Spatially irradiating the device based on the optimal excitation wavelength of the selected PN junction to detect the optimal fluorescence wavelength of the selected PN junction; Step S3: Periodically spatially irradiating the device based on the optimal fluorescence wavelength of the selected PN junction to diagnose the fluorescence decay relationship of the selected PN junction over time; Step S4: Diagnosing and determining the fluorescence lifetime of the selected PN junction based on the fluorescence decay relationship of the selected PN junction over time; Step S5: Replacing the selected PN junction and repeating steps S1 to S4 until the fluorescence lifetimes of multiple PN junctions of the device are determined; Step S6: Combining the fluorescence lifetimes of the multiple PN junctions, the current-voltage characteristics of the device, and the spatial irradiation type of the device, determining the normalized power decay curve of the device, wherein the fitting formula for the normalized power decay curve is:

[0008]

[0009] Where y is the normalized power, x is the space irradiation dose, and A, B, and P are parameters to be fitted; and step S7: based on the normalized power decay curve of the device, evaluate the total cumulative space irradiation, cumulative operating time of the device, and predict the remaining lifetime of the device.

[0010] Preferably, in some embodiments of the present invention, step S4 includes: determining the kinetic parameters of the device based on the fluorescence lifetime of the selected PN junction and the current-voltage characteristics of the device, wherein the kinetic parameters include the exciton diffusion length and diffusion coefficient of the selected PN junction.

[0011] Preferably, in some embodiments of the present invention, step S4 includes: determining the exciton diffusion length of the selected PN junction by fitting or direct detection; and verifying the fluorescence lifetime of the selected PN junction based on the exciton diffusion length.

[0012] Preferably, in some embodiments of the present invention, the plurality of PN junctions include some or all of the PN junctions of the device.

[0013] Preferably, in some embodiments of the present invention, step S3 includes: determining the fluorescence decay relationship of the selected PN junction over time based on the relationship between the fluorescence intensity of the selected PN junction and time.

[0014] Preferably, in some embodiments of the present invention, step S4 includes: determining the fluorescence lifetime of the selected PN junction by fitting the fluorescence decay relationship of the selected PN junction over time based on a series function.

[0015] Preferably, in some embodiments of the present invention, the spatial irradiation type of the device includes one or more of atomic oxygen, protons, or electrons.

[0016] Preferably, in some embodiments of the present invention, in step S3, the light source for spatially irradiating the device is a monochromatic light source with an irradiation frequency of 20MHz.

[0017] Preferably, in some embodiments of the present invention, before step S1, the method further includes: determining the type of the device, wherein the type of the device includes a battery-type device, a gate-probe device, and a gateless probe device; and when the type of the device is a gate-probe device, adjusting the gate voltage of the gate-probe device.

[0018] Furthermore, the performance evaluation system for the multi-junction photoelectric device provided according to the second aspect of the present invention is used to implement the non-destructive comprehensive measurement and evaluation method for the spatial serviceability performance of the multi-junction photoelectric device provided in the first aspect of the present invention. The performance evaluation system for the multi-junction photoelectric device includes: a quantum conversion characteristic measurement system, which determines the optimal fluorescence wavelength of the selected PN junction based on the quantum transfer characteristics of the selected PN junction of the device; a fluorescence lifetime detection system, which determines the fluorescence lifetime of the selected PN junction under periodic spatial irradiation at the optimal fluorescence wavelength of the selected PN junction; and a fitting system, which determines the normalized power decay curve of the device based on the fluorescence lifetimes of multiple PN junctions of the device, the current-voltage characteristics of the device, and the spatial irradiation type of the device.

[0019] Preferably, in some embodiments of the present invention, the device further includes: an irradiation device for providing a light source to the device; and an IV tester for obtaining the current-voltage characteristics of the device. Attached Figure Description

[0020] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0021] Figure 1 A schematic diagram of a performance evaluation system for multi-junction photoelectric devices provided according to some embodiments of the present invention is shown;

[0022] Figure 2 A flowchart is shown of a non-destructive comprehensive measurement and evaluation method for the spatial serviceability of multi-junction photoelectric devices provided according to some embodiments of the present invention;

[0023] Figure 3 A current-voltage characteristic curve of a solar cell according to a preferred embodiment of the present invention is shown;

[0024] Figure 4 A graph showing the relationship between the external quantum efficiency and wavelength of a solar cell according to a preferred embodiment of the present invention is shown.

[0025] Figure 5 A graph showing the relationship between fluorescence excitation and wavelength of a solar cell according to a preferred embodiment of the present invention is shown.

[0026] Figure 6 A graph showing the relationship between fluorescence intensity and time for a solar cell according to a preferred embodiment of the present invention is shown; and

[0027] Figure 7 A fitting plot of normalized power and space irradiance dose for a solar cell provided according to a preferred embodiment of the present invention is shown.

[0028] Figure label:

[0029] 100: Performance evaluation system for multi-junction photoelectric devices;

[0030] 101: Irradiation device;

[0031] 102: IV tester;

[0032] 110: Quantum conversion property measurement system;

[0033] 120: Fluorescence lifetime detection system;

[0034] 130: Fitting system;

[0035] 200: A non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices;

[0036] 401, 402, 403: Curves;

[0037] 501, 502, 503: Curves;

[0038] 601, 602: Curves;

[0039] 701: Fitted curve; and

[0040] S1~S7: Steps. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as referring to the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the system described must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0044] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0045] As mentioned above, photoelectric devices used in space environments are exposed to space radiation from atomic oxygen, electrons, and protons. Complex combinations and prolonged space radiation can lead to performance degradation or even failure of photoelectric devices.

[0046] This invention provides a non-destructive comprehensive measurement and evaluation method for the space service performance of multi-junction photoelectric devices and a performance evaluation system for multi-junction photoelectric devices. Based on data such as quantum transfer characteristics and fluorescence lifetime of the device under equivalent space irradiation dose, and combined with a normalized fitting numerical method, the method obtains the variation law and trend of the device's photoelectric performance. This enables non-destructive testing of photoelectric devices, evaluates the cumulative total space irradiation and cumulative operating time of photoelectric devices in a space environment, and predicts the remaining lifetime of the photoelectric devices. Furthermore, this non-destructive comprehensive measurement and evaluation method for the space service performance of multi-junction photoelectric devices is widely adaptable, simple to operate, and easy to implement.

[0047] In some non-limiting embodiments, the non-destructive comprehensive measurement and evaluation method for the spatial service performance of the multi-junction photoelectric device provided in the first aspect of the present invention can be implemented via the performance evaluation system for the multi-junction photoelectric device provided in the second aspect of the present invention.

[0048] Those skilled in the art will understand that the embodiments of the non-destructive comprehensive measurement and evaluation method for the spatial service performance of multi-junction photoelectric devices are merely some non-limiting implementations provided by the present invention, intended to clearly demonstrate the main concepts of the invention and provide some specific solutions that are easy for the public to implement, rather than being intended to limit all modules, all functions, or all operating modes of the performance evaluation system for multi-junction photoelectric devices. Similarly, the performance evaluation system for multi-junction photoelectric devices is also merely a non-limiting implementation provided by the present invention, and does not constitute a limitation on the executing entities and execution order of the steps in the non-destructive comprehensive measurement and evaluation method for the spatial service performance of these multi-junction photoelectric devices.

[0049] Before implementing a non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices, the photoelectric devices can be diagnosed first. In some embodiments, the diagnosis of photoelectric devices may include the type of photoelectric device, electrode structure, electrical characteristics, photoelectric characteristics, and quantum transfer characteristics, etc.

[0050] Those skilled in the art can determine the type and electrode structure of a photoelectric device using one or more methods, such as direct visual observation, imaging with an optical microscope, or imaging with an electron microscope. In some embodiments, the device response can also be determined based on the measurement of the photoelectric device's current-voltage characteristic curve, thereby determining the device type. The types of photoelectric devices may include battery-type devices, gate-detector devices, and gateless detector devices. The electrode structure of a photoelectric device can be divided into two-electrode or three-electrode types.

[0051] Before implementing a non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices, when the photoelectric device is a gate-detector type device, the gate voltage of the gate-detector device can be adjusted. In some embodiments, the adjustment of the gate voltage of the gate-detector device can be performed under various illumination conditions of the irradiation device, and the adjustment range can be -40V to 40V. Preferably, the gate voltage value can be selected as the gate voltage at which the photoelectric device obtains the optimal light response.

[0052] Please refer to Figure 1 , Figure 1 A schematic diagram of a performance evaluation system for multi-junction photoelectric devices provided according to some embodiments of the present invention is shown.

[0053] like Figure 1As shown, the performance evaluation system 100 for multi-junction photoelectric devices may include an irradiation device 101. The irradiation device 101 can be used to provide a light source for the photoelectric device. The illumination conditions for the photoelectric device can be a combination of one or more conditions, such as no light source spatial irradiation, monochromatic light spatial irradiation, and natural light (and polychromatic light) spatial irradiation. Furthermore, the illumination conditions provided by the irradiation device 101 can be illumination conditions with various adjustable power levels. In addition, the spatial irradiation type of the light source provided by the irradiation device 101 can be one or more combinations of atomic oxygen, protons, and electrons.

[0054] Those skilled in the art can determine the quantum transfer characteristics of a photoelectric device by measuring its external quantum efficiency (EQE) or internal quantum efficiency (IQE).

[0055] In some embodiments, the quantum transfer characteristics of a photoelectric device are determined by measuring its external quantum efficiency. Specifically, under illumination provided by the irradiation device 101, the quantum transfer characteristics of the photoelectric device under test are determined by measuring the mathematical relationships between the ratio of the number of photoelectrons (photogenerated carriers) to the number of incident photons, the ratio of the number of photons emitted to the number of injected carriers, and other physical quantities that can be normalized to the above parameters.

[0056] In other embodiments, the quantum transfer characteristics of the photoelectric device are determined by measuring its internal quantum efficiency. Specifically, under illumination provided by the irradiation device 101, the quantum transfer characteristics of the photoelectric device under test are determined by measuring the ratio of the number of photons emitted by exciton recombination inside the device to the number of injected charge carriers, and the mathematical relationship between other physical quantities that can be normalized to the above parameters.

[0057] like Figure 1 As shown, the performance evaluation system 100 for multi-junction photoelectric devices may include a quantum conversion characteristic measurement system 110. The quantum conversion characteristic measurement system 110 can determine the optimal fluorescence wavelength of the PN junction of the photoelectric device based on the quantum transfer characteristics of the PN junction.

[0058] Please refer to Figure 2 , Figure 2 A flowchart is shown of a non-destructive comprehensive measurement and evaluation method for the spatial serviceability of multi-junction photoelectric devices provided according to some embodiments of the present invention.

[0059] like Figure 2As shown, the non-destructive comprehensive measurement and evaluation method 200 for the spatial serviceability of multi-junction photoelectric devices may include step S1: based on the quantum transfer characteristics of the device, detecting the optimal excitation wavelength of the selected PN junction of the device.

[0060] In some preferred embodiments, a PN junction of the device can be selected, and the optimal excitation wavelength of the selected PN junction can be detected based on the quantum transfer characteristics of the device. The quantum transfer characteristics of the PN junction of the photoelectric device can be determined by the external quantum efficiency method. Specifically, the photoelectric device can be placed under the irradiation device 101 of the performance evaluation system 100 for multi-junction photoelectric devices. Here, the light source irradiating the photoelectric device by the irradiation device 101 is a monochromatic light source.

[0061] Subsequently, the wavelength of the monochromatic light source was gradually adjusted, and the ratio of photogenerated carriers to incident photons at the selected PN junction of the photoelectric device was recorded at the varying wavelengths. Plotting the wavelength of the monochromatic light source incident on the photoelectric device on the x-axis and the ratio of photogenerated carriers to incident photons at the varying wavelengths on the y-axis, an EQE (external quantum efficiency) curve for the selected PN junction of the photoelectric device can be obtained. Based on the EQE curve, the wavelength at which the optimal quantum transfer efficiency is achieved can be determined as the optimal excitation wavelength for the PN junction of the photoelectric device.

[0062] like Figure 1 As shown, the performance evaluation system 100 for multi-junction photoelectric devices may include a fluorescence lifetime detection system 120. The fluorescence lifetime detection system 120 can determine the fluorescence lifetime of the PN junction of the photoelectric device under spatial irradiation at the optimal fluorescence wavelength of the PN junction.

[0063] Please continue to refer to this. Figure 2 The non-destructive comprehensive measurement and evaluation method 200 for the spatial service performance of multi-junction photoelectric devices may include step S2: spatially irradiating the device based on the optimal excitation wavelength of the selected PN junction to detect the optimal fluorescence wavelength of the selected PN junction.

[0064] The fluorescence excitation conditions of the PN junction of the photoelectric device can be achieved under various illumination conditions provided by the irradiation device 101. In some preferred embodiments, the fluorescence excitation condition of the PN junction of the photoelectric device can be the optimal excitation wavelength of the selected PN junction determined in step S1, that is, the optimal excitation wavelength is used as the wavelength of the light source of the irradiation device 101. By using the optimal excitation wavelength of the selected PN junction as the wavelength of the light source of the irradiation device 101, the optimal fluorescence wavelength of the selected PN junction of the photoelectric device can be determined under the spatial irradiation of the irradiation device 101.

[0065] For example, in some non-limiting embodiments, the selected PN junction is the i-th PN junction, based on the optimal excitation wavelength λ of the i-th PN junction. iEQE The i-th PN junction is detected using the fluorescence excitation wavelength. Specifically, the wavelength of the adjustable monochromatic light source of the irradiation device 101 irradiating the photoelectric device is adjusted to the optimal excitation wavelength λ. i EQE Then, the wavelength and intensity of the emitted light from the device are recorded. The photoluminescence (PL) spectrum is obtained by plotting the emitted light wavelength on the x-axis and the intensity on the y-axis, thereby determining the relationship between the fluorescence excitation of the i-th PN junction and the wavelength. Here, the wavelength at the point of maximum intensity is the optimal fluorescence wavelength λ for the i-th PN junction. i PL Here, fluorescence excitation is the process of stimulated emission of photons by electrons at the PN junction, which includes information about the electronic state.

[0066] Please continue to refer to this. Figure 2 The non-destructive comprehensive measurement and evaluation method 200 for the space service performance of multi-junction photoelectric devices may include step S3: periodically irradiating the device in space based on the optimal fluorescence wavelength of the selected PN junction to diagnose the fluorescence decay relationship of the selected PN junction over time.

[0067] The fluorescence decay relationship of the selected PN junction in a photoelectric device over time can be determined under spatial irradiation by a light source with a wavelength equal to the optimal fluorescence wavelength of the selected PN junction.

[0068] In determining the fluorescence decay relationship of the selected PN junction in the photoelectric device over time, the fluorescence excitation conditions of the selected PN junction can be achieved under various illumination conditions provided by the irradiation device 101. In some preferred embodiments, the fluorescence excitation condition of the selected PN junction can be the optimal fluorescence wavelength of the selected PN junction determined in step S2, that is, the optimal fluorescence wavelength is used as the wavelength of the light source of the irradiation device 101. By using the optimal fluorescence wavelength as the wavelength of the light source of the irradiation device 101, the fluorescence decay relationship of the selected PN junction in the photoelectric device over time can be determined under the spatial irradiation of the irradiation device 101.

[0069] Optionally, the decay relationship of fluorescence at the PN junction of a photoelectric device over time can be determined by the fluorescence intensity versus sampling time, or by the mathematical relationships between the number of fluorescence photons versus the number of detection steps, fluorescence intensity versus the number of detection steps, the number of fluorescence photons versus the sampling time, and other physical quantities normalizable to the above parameters. Since there may be detection losses in the detector, the term "fluorescence intensity" in this context should be understood in a colloquial sense, referring to the fluorescence signal response intensity detected by the detector used. No further distinction will be made thereafter. Sampling time can also be expressed by the number of sampling steps.

[0070] In some embodiments, the fluorescence decay relationship of the selected PN junction in the photoelectric device over time can be determined by the fluorescence intensity versus sampling time, i.e., TRPL (Time-Resolved Photoluminescence).

[0071] Specifically, when detecting the i-th PN junction of the photoelectric device, the wavelength of the monochromatic light source used to irradiate the photoelectric device is adjusted to the optimal fluorescence wavelength λ. i PL The emission frequency of the monochromatic light source is adjusted to periodically irradiate the photoelectric device in space, with the preferred emission frequency being 20MHz. Then, clutter photons are filtered out using a monochromator, and the relationship between the number of emitted photons and the counting time is recorded using an ultrafast detector. The number of emitted photons is plotted on the vertical axis, and the counting time on the horizontal axis, respectively, to obtain the TRPL of the i-th PN junction of the photoelectric device.

[0072] Please continue to refer to this. Figure 2 The non-destructive comprehensive measurement and evaluation method 200 for the spatial service performance of multi-junction photoelectric devices may include step S4: diagnosing and determining the fluorescence lifetime of the selected PN junction based on the fluorescence decay relationship of the selected PN junction over time.

[0073] In some embodiments, the fluorescence lifetime of the selected PN junction in the photoelectric device can be obtained by fitting a mathematical relationship between a series function (e.g., double e-exponent, single e-exponent) and other physical quantities that can be normalized to the above parameters.

[0074] For example, in some preferred embodiments, the fluorescence lifetime of the PN junction of the photoelectric device can be determined by fitting the fluorescence decay relationship of the PN junction of the photoelectric device over time based on the bie exponent.

[0075] Specifically, in some embodiments, the fluorescence decay relationship of the selected PN junction of the photoelectric device over time is determined based on the TRPL spectrum. Subsequently, the non-destructive comprehensive measurement and evaluation method 200 for the spatial performance of multi-junction photoelectric devices can determine the fluorescence intensity of the selected PN junction over time from the TRPL spectrum, thereby determining the fluorescence decay relationship over time. Then, the non-destructive comprehensive measurement and evaluation method 200 for the spatial performance of multi-junction photoelectric devices can fit the TRPL spectrum using the bie exponent.

[0076] Here, the double-e index can be preferably:

[0077]

[0078] Where t is time, D(t) is the ordinate, i.e., fluorescence intensity, and A1, A2, y0, τ1, and τ2 are fitting parameters. The data of the TRPL spectrum on both the x and y axes are imported into data processing software, and the least squares fitting formula is used. In this preferred embodiment, the larger of A1 and A2 can be simply selected. i The corresponding term of the value τ i Fluorescence lifetime of the PN junction selected for photoelectric devices.

[0079] Thus, the performance evaluation system 100 for multi-junction photoelectric devices and the non-destructive comprehensive measurement and evaluation method 200 for the spatial serviceability of multi-junction photoelectric devices provided by this invention determine the optimal fluorescence wavelength of the selected PN junction at the optimal excitation wavelength of the selected PN junction, and determine the fluorescence decay relationship of the selected PN junction over time at the optimal fluorescence wavelength, thereby measuring the fluorescence lifetime of the selected PN junction. Compared with existing measurement methods that require dissecting the device, the non-destructive comprehensive measurement and evaluation method 200 for the spatial serviceability of multi-junction photoelectric devices is non-destructive. By using photodetection for diagnosis, detection, and measurement, the integrity of the device's structure and function can be maintained, protecting the integrity of valuable samples and enabling them to continue to be used or undergo other required testing.

[0080] Furthermore, the fluorescence lifetime of the selected PN junction in the photoelectric device and the short-circuit photocurrent can be mutually derived. The short-circuit photocurrent can be determined based on the device's current-voltage characteristics. The fluorescence lifetime τ of the selected PN junction in the photoelectric device and the short-circuit photocurrent I... SC The relationship can be shown as follows:

[0081]

[0082] Where S is the area of ​​the selected PN junction, G0 is the exciton (fluorescence) density generation rate of the selected PN junction, L is the exciton diffusion length of the selected PN junction, and D... exc It is the exciton diffusion constant of the selected PN junction.

[0083] According to formula (2), the short-circuit photocurrent I is determined based on the fluorescence lifetime τ of the selected PN junction of the photoelectric device and the current-voltage characteristics of the device. SC This allows us to determine the kinetic parameters of the device. These kinetic parameters can include the exciton diffusion length L and exciton diffusion coefficient D of the selected PN junction. exc Those skilled in the art can determine the degree of degradation of the internal structure of a device based on kinetic parameters.

[0084] In addition, the fluorescence lifetime τ and short-circuit photocurrent I of the selected PN junction in the photoelectric device SC Exciton diffusion length L, exciton diffusion constant D excThe relationships between various physical quantities can be mutually derived and verified. For example, in some embodiments, the exciton diffusion length L can be determined by fitting methods or by direct observation using scanning photocurrent microscopy. Then, based on the determined exciton diffusion length L, the fluorescence lifetime τ of the selected PN junction in the photoelectric device can be derived and verified. The device's kinetic parameters can be applied to the materials of the photoelectric device to comprehensively evaluate its space-use performance in a space environment.

[0085] Please continue to refer to this. Figure 2 The non-destructive comprehensive measurement and evaluation method 200 for the spatial service performance of multi-junction photoelectric devices may include step S5: replacing the selected PN junction and repeating steps S1 to S4 until the fluorescence lifetime of the multiple PN junctions of the device is determined.

[0086] The photoelectric device comprises multiple PN junctions. In some embodiments, the non-destructive comprehensive measurement and evaluation method 200 for the space utilization performance of a multi-junction photoelectric device can replace the selected PN junctions and repeat steps S1 to S4 to determine the fluorescence lifetime of the multiple PN junctions. Here, the multiple PN junctions of the photoelectric device being measured may include some or all of the PN junctions. In some embodiments, the PN junctions of the photoelectric device may be 1 to 6 PN junctions.

[0087] As will be understood by those skilled in the art, the non-destructive comprehensive measurement and evaluation method 200 for the spatial performance of multi-junction photoelectric devices provided by the present invention also includes the measurement of the fluorescence lifetime of a single, specified PN junction. The local performance of the multi-junction photoelectric device can be evaluated by measuring the fluorescence lifetime of a single, specified PN junction.

[0088] Furthermore, the performance evaluation system 100 for multi-junction photoelectric devices may also include a fitting system 130. The fitting system 130 can determine the normalized power decay curve of the photoelectric device based on the fluorescence lifetime of the multiple PN junctions of the photoelectric device, the current-voltage characteristics of the photoelectric device, and the type of space irradiation.

[0089] Please continue to refer to this. Figure 2 The non-destructive comprehensive measurement and evaluation method 200 for the spatial service performance of multi-junction photoelectric devices may include step S6: combining the fluorescence lifetime of multiple PN junctions, the current-voltage characteristics of the device and the spatial irradiation type of the device to determine the normalized power decay curve of the device.

[0090] The current-voltage (V / V) characteristics of a photoelectric generator can be obtained through a combination of methods, such as applying voltage and measuring current or applying current and measuring voltage. The V / V characteristics of a photoelectric generator can be determined by one or more of the following characteristics: the device's IV diagram, its current response under light, its voltage response under light, its power, and its normalized power.

[0091] like Figure 1 As shown, the performance evaluation system 100 for multi-junction photoelectric devices may include an IV tester 102. Under various illumination conditions illuminating the device 101, the IV tester 102 can be used for automated testing to directly obtain the IV data of the photoelectric device on a computer. Based on the obtained IV data, the current-voltage characteristics of the photoelectric device can be determined, and the operating condition of the photoelectric device can be verified. It can also be used to determine the type of photoelectric device.

[0092] Preferably, the process of performing diagnostic measurements on the photoelectric device using the IV tester 102 can be performed before step S1.

[0093] Based on the IV data of the photoelectric device obtained directly using the IV tester 102, the current-voltage characteristics of the photoelectric device can be determined.

[0094] The normalized power decay curve can be fitted using methods such as least squares, minimizing the ∞-norm, and minimizing the 1-norm. The parameters in the normalization formula can be empirical values, experimental values, and their weighted combinations. Preferably, the normalized power decay curve can be determined based on the normalized power, normalized current, and other physical quantities simplified to the above parameters obtained from the volt-ampere characteristics of the photoelectric device.

[0095] Based on the current-voltage characteristics of the photoelectric device and the type of space irradiation, a fitting formula for the normalized power decay curve of the photoelectric device can be determined. Here, the type of space irradiation can be one or more combinations of atomic oxygen, protons, electrons, etc.

[0096] The fitting formula for the normalized power decay curve provided by this invention can be based on the least squares method, specifically as shown in formula (3):

[0097]

[0098] Where y is the normalized power, x is the space irradiation dose, and A, B, and P are the parameters to be fitted. The normalized power of the photoelectric device can be determined by the IV plot obtained from the IV meter.

[0099] According to the fitting formula of the normalized power decay curve shown in formula (3), the non-destructive comprehensive measurement and evaluation method 200 for the space service performance of multi-junction photoelectric devices provided by the present invention can fit the normalized power decay trend of multi-junction photoelectric devices under space environment (e.g., space irradiation of atomic oxygen, protons, and electrons).

[0100] Then, the normalized power y is plotted as the ordinate and the spatial irradiation dose x as the abscissa to create a normalized power decay curve. The normalized power is fitted using formula (3), thereby determining the total cumulative radiation received by the photoelectric device.

[0101] In the fitting process, specifically, for a given dataset of normalized power y and space irradiation dose x of length n {(x1,y1),(x2,y2),…,(x... k ,y k ),…,(x n ,y n )}, where k is the index of the data point, in a function family containing all types of functions. Determine the function S * (x) minimizes the sum of squared biases of the dataset, i.e., minimizes the following formula (4):

[0102]

[0103] Preferably, the determined function S for fitting the normalized power decay curve... * (x) can be represented as follows:

[0104]

[0105] Where A, B, and P are the parameters to be fitted. In some embodiments, the parameters A, B, and P can be randomly assigned a value first to obtain A. j B j P j Then, {x} i Substituting} into the equation, we get {S(A)} j B j ,P j ,x i )}, calculate the sum of squared deviations y(A) j B j ,P j ):

[0106]

[0107] After that, A j B j P jVariations are made within a small numerical range. For example, ε can be set to a specified precision to obtain A. j+1 =A j ±ε、B j+1 =B j ±ε、P j+1 =P j ±ε, and the results of the changes are added, subtracted and combined, resulting in a total of l = 1, 2... 8, that is, a total of 8 {A j+1,l B j+1,l ,p j+1,l}

[0108] Using formula (6) to analyze the 8 {A} j+1,l B j+1,l ,p j+1,l Continue calculating the sum of squared deviations {y} l (A j+1 B j+1 ,p j+1 )|l=1,2…8}. Compare each y l (A j+1 B j+1 ,p j+1 ) and y(A j B j ,p j ), choose to let y(A) j+1 B j+1 ,p j+1 Take the minimum value and it is not greater than y(A) j B j ,p j ) of {A j+1,l B j+1,l ,p j+1,l When combining, update the fitted parameters {A} j B j ,p j Then, continue repeating the above steps until formula (7) is satisfied:

[0109] |y(A j+1 B j+1 ,p j+1 )-y(A j B j ,p j )|<ε (7)

[0110] Therefore, the parameters after fitting A, B, and P can be determined, and the normalized power decay curve can be determined based on the prediction formula of normalized power y and space irradiation dose x determined by the fitting.

[0111] Those skilled in the art can also use the fitting system 130 to verify the current-voltage characteristics of the photoelectric device based on the fluorescence lifetime of multiple PN junctions of the photoelectric device, and then determine the normalized power decay curve of the photoelectric device based on the fluorescence lifetime of the PN junctions of the photoelectric device.

[0112] Therefore, determining the fluorescence lifetime of multiple PN junctions in a photoelectric device allows for a comprehensive evaluation of the measured current-voltage characteristics of the device. Furthermore, the normalized power decay curve of the photoelectric device can also be deduced based on the fluorescence lifetime of its multiple PN junctions.

[0113] like Figure 2 As shown, the non-destructive comprehensive measurement and evaluation method 200 for the spatial service performance of multi-junction photoelectric devices may include step S7: determining the cumulative total spatial irradiance and cumulative operating time of the device and predicting the remaining lifetime of the device based on the normalized power decay curve of the device.

[0114] Based on the normalized power decay curve of the device, the cumulative spatial irradiance and cumulative operating time of the photoelectric device can be determined, and the effective operating life can be predicted.

[0115] Thus, the non-destructive comprehensive measurement and evaluation method for the space-use performance of multi-junction photoelectric devices can determine the fluorescence lifetime of multiple PN junctions based on the quantum transfer characteristics of the photoelectric device under equivalent space irradiation dose. The kinetic parameters of the PN junctions can be determined based on their fluorescence lifetimes, thereby elucidating the dynamic process of the photoelectric device. Furthermore, by combining the normalized fitting numerical method of the non-destructive comprehensive measurement and evaluation method for the space-use performance of multi-junction photoelectric devices, the variation law and trend of the photoelectric performance of the photoelectric device can be obtained, and the cumulative space irradiation and cumulative operating time of the photoelectric device can be determined, thus providing a basis and reference for the effective operating life of key aerospace semiconductor devices.

[0116] This non-destructive comprehensive measurement and evaluation method for the space service performance of multi-junction photoelectric devices can not only evaluate solar cells but also be applied to photoelectric devices based on mechanisms such as photoelectric generation, including photodetectors. It has broad applicability and practicality, and can be extended to devices of different materials and structures. It provides valuable theoretical guidance and practical basis for further improving the performance of photoelectric devices and predicting the on-orbit operating time of aerospace semiconductor devices, offering strong technical support for the application of space-based multi-junction photoelectric devices. Furthermore, the data related to the space service performance of photoelectric devices obtained through the non-destructive comprehensive measurement and evaluation method provided by this invention has profound guiding significance for a deeper understanding of photoelectric conversion mechanisms, performance bottlenecks, and optimization directions.

[0117] The following is a specific, non-limiting preferred embodiment, which further elaborates on the non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices proposed in this invention.

[0118] In this preferred embodiment, GaInP2 / GaAs / In 0.3 Ga 0.7 Taking a real triple-junction flexible gallium arsenide solar cell as an example, we can first conduct observational diagnosis to determine that the solar cell is a two-electrode device.

[0119] Please refer to Figure 3 , Figure 3 A current-voltage characteristic curve of a solar cell provided according to a preferred embodiment of the present invention is shown.

[0120] Preferably, the IV data of the solar cell can first be obtained using an IV tester. In this preferred embodiment, the IV data of the solar cell under irradiation by an irradiation device can be obtained by applying pressure and measuring current to determine the current-voltage characteristics of the solar cell.

[0121] Solar cells can be viewed as devices with high current and high voltage output and a wide-bandwidth spectral response. For example... Figure 3 As shown, the solar cell exhibits stable voltage and current responses, indicating that the device is undamaged and in good working order. Furthermore, the device can output high voltage and current when exposed to sunlight, and this output is not significantly dependent on the wavelength of the sunlight. Therefore, the device can be identified as a battery-type device.

[0122] Please refer to Figure 4 , Figure 4 A graph showing the relationship between the external quantum efficiency and wavelength of a solar cell according to a preferred embodiment of the present invention is provided.

[0123] The tunable monochromatic light source of the irradiation device has a wavelength range of 200–1400 nm. Based on the PN junction type of the solar cell, the solar cell is excited using the monochromatic light source of the irradiation device to test the relationship between the external quantum conversion efficiency (EQE, %) and wavelength (wavelength, nm). Figure 4 As shown, curve 401 represents the relationship between the external quantum conversion efficiency of the first PN junction of the solar cell and the wavelength, curve 402 represents the relationship between the external quantum conversion efficiency of the second PN junction of the solar cell and the wavelength, and curve 403 represents the relationship between the external quantum conversion efficiency of the third PN junction of the solar cell and the wavelength. According to... Figure 4The response wavelengths are widely distributed across the solar spectrum, further verifying that the device is a cell-type device. Simultaneously, the optimal quantum efficiency wavelength (i.e., the optimal excitation wavelength) for each junction of the solar cell can be determined. The optimal excitation wavelength for the first PN junction is 532 nm, for the second PN junction it is 650 nm, and for the third PN junction it is 1060 nm.

[0124] Please refer to Figure 5 , Figure 5 A graph showing the relationship between fluorescence excitation and wavelength of a solar cell according to a preferred embodiment of the present invention is shown.

[0125] The wavelength of the tunable monochromatic light source used in the irradiation device was adjusted to the optimal excitation wavelength of 532 nm for the first PN junction to irradiate the solar cell in space. The relationship between the fluorescence excitation of the first PN junction of the solar cell and the wavelength was plotted with wavelength (in nm) on the x-axis and intensity (in Augmentation Units, au) on the y-axis. The relationship between the fluorescence excitation of the first PN junction of the solar cell and the wavelength is as follows: Figure 5 As shown in curve 501, the optimal fluorescence wavelength of the first PN junction of the solar cell can be determined to be 632 nm based on the relationship between fluorescence excitation and wavelength.

[0126] Similarly, by adjusting the wavelength of the tunable monochromatic light source of the irradiation device to the optimal excitation wavelength of the second PN junction, 650 nm, to irradiate the solar cell in space, the relationship between the fluorescence excitation of the second PN junction of the solar cell and the wavelength can be obtained, such as... Figure 5 As shown in curve 502, the optimal fluorescence wavelength of the second PN junction in a solar cell can be determined to be 860 nm based on the relationship between fluorescence excitation and wavelength. By adjusting the wavelength of the tunable monochromatic light source of the irradiation device to the optimal excitation wavelength of the third PN junction (1060 nm) for space irradiation of the solar cell, the relationship between fluorescence excitation and wavelength of the third PN junction can be obtained, as shown in curve 502. Figure 5 As shown in curve 503, the optimal fluorescence wavelength of the third PN junction in a solar cell can be determined to be 1225 nm based on the relationship between fluorescence excitation and wavelength.

[0127] Please refer to Figure 6 , Figure 6 A graph showing the relationship between fluorescence intensity and time for a solar cell provided according to a preferred embodiment of the present invention is shown.

[0128] The wavelength of the tunable monochromatic light source used for irradiation was adjusted to the optimal fluorescence wavelength of the first PN junction, 632 nm, to irradiate the solar cell in space. The fluorescence intensity of the first PN junction of the solar cell was plotted against time (in ns) on the x-axis and intensity (in au) on the y-axis. Figure 6 As shown in curve 601. Correspondingly, the wavelength of the tunable monochromatic light source irradiating the device can be adjusted to the optimal fluorescence wavelength of the third PN junction, 1255 nm, to irradiate the solar cell in space, thereby obtaining the relationship between the fluorescence intensity of the third PN junction of the solar cell and time, as shown in... Figure 6 As shown in curve 602, the fluorescence intensity of the second PN junction of a solar cell versus time can be determined in the same way.

[0129] Then, by fitting the bie exponent as follows: Figure 6 The fluorescence intensity versus time relationship is shown to determine the fluorescence lifetime of each PN junction. Based on a double-e-exponential fitting of the fluorescence intensity versus time relationship of the first PN junction, the fluorescence lifetime of the first PN junction is determined to be 31 ps. Correspondingly, a double-e-exponential fitting of the fluorescence intensity versus time relationship of the third PN junction yields a fluorescence lifetime of 150 ps. The fluorescence lifetime of the second PN junction can also be determined using a double-e-exponential fitting of the fluorescence intensity versus time relationship of the second PN junction.

[0130] Based on the determined fluorescence lifetime of each PN junction, the kinetic parameters of the solar cell can be determined, and based on the kinetic parameters, the degree of degradation of the internal structure of the solar cell can be assessed.

[0131] Please refer to Figure 7 , Figure 7 A fitting plot of normalized power and space irradiance dose for a solar cell provided according to a preferred embodiment of the present invention is shown.

[0132] like Figure 7 As shown, the vertical axis represents normalized power (in au), and the horizontal axis represents space radiation dose (in atoms cm). -2 The normalized power of the solar cell is determined based on its current-voltage characteristics. In this preferred embodiment, the space irradiation type is atomic oxygen. The fitting formula between the normalized power and the space irradiation dose is:

[0133]

[0134] Where y is the normalized power, x is the space irradiation dose, and A, B, and P are the parameters to be fitted.

[0135] Based on the fitting formula of normalized power and space irradiation dose, Figure 7 By fitting the experimental data points, the fitting curve 701 of the solar cell can be determined, namely the normalized power decay curve. Based on the measured parameters such as the fluorescence lifetime of multiple PN junctions of the solar cell and the normalized power decay curve, the cumulative total space irradiance and cumulative operating time of the device are jointly evaluated, providing a basis and reference for the effective operating life.

[0136] In summary, the non-destructive comprehensive measurement and evaluation method for the spatial service performance of multi-junction photoelectric devices provided by this invention can diagnose multi-junction, "photoelectric" type photoelectric devices, obtain the characteristics of each PN junction of the photoelectric device non-destructively under space irradiation conditions, and effectively predict the effective service life and other performance characteristics of the photoelectric device. The non-destructive comprehensive measurement and evaluation method for the spatial service performance of multi-junction photoelectric devices provided by this invention is universal, non-destructive, effective, simple, efficient, and scalable.

[0137] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0138] Those skilled in the art will understand that information, signals, and data can be represented using any of a variety of different techniques and arts. For example, the data, instructions, commands, information, signals, bits, symbols, and chips described throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0139] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this hardware-software interchangeability, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each particular application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0140] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices, characterized in that, include: Step S1: Based on the quantum transfer characteristics of the device, detect the optimal excitation wavelength of the selected PN junction of the device; Step S2: Spatially irradiate the device based on the optimal excitation wavelength of the selected PN junction to detect the optimal fluorescence wavelength of the selected PN junction; Step S3: Periodically spatially irradiate the device based on the optimal fluorescence wavelength of the selected PN junction to diagnose the fluorescence decay relationship of the selected PN junction over time; Step S4: Based on the fluorescence decay relationship of the selected PN junction over time, diagnose and determine the fluorescence lifetime of the selected PN junction; Step S5: Replace the selected PN junction and repeat steps S1 to S4 until the fluorescence lifetime of the multiple PN junctions of the device is determined. Step S6: Combining the fluorescence lifetime of the multiple PN junctions, the current-voltage characteristics of the device, and the space irradiation type of the device, determine the normalized power decay curve of the device. The fitting formula for the normalized power decay curve is: Where y is the normalized power, x is the space irradiation dose, and A, B, and P are the parameters to be fitted; and Step S7: Based on the normalized power decay curve of the device, evaluate the total cumulative spatial irradiance and cumulative operating time of the device, and predict the remaining lifetime of the device.

2. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, Step S4 includes: Based on the fluorescence lifetime of the selected PN junction and the current-voltage characteristics of the device, the kinetic parameters of the device are determined, including the exciton diffusion length and diffusion coefficient of the selected PN junction.

3. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, Step S4 includes: The exciton diffusion length of the selected PN junction is determined by fitting or direct detection; and The fluorescence lifetime of the selected PN junction is verified based on the exciton diffusion length.

4. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, The plurality of PN junctions includes some or all of the PN junctions of the device.

5. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, Step S3 includes: Based on the relationship between the fluorescence intensity of the selected PN junction and time, the fluorescence decay relationship of the selected PN junction over time is determined.

6. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, Step S4 includes: The fluorescence lifetime of the selected PN junction is determined by fitting the fluorescence decay relationship of the selected PN junction over time using a series function.

7. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, The space irradiation type of the device includes one or more of atomic oxygen, protons, or electrons.

8. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, In step S3, the light source for spatial irradiation of the device is a monochromatic light source with an irradiation frequency of 20MHz.

9. The non-destructive comprehensive measurement and evaluation method for the spatial performance of multi-junction photoelectric devices as described in claim 1, characterized in that, Before step S1, the following steps are also included: The type of the device is determined, including battery-type devices, gate-type probe devices, and gateless probe devices; and When the device is a gate-sensing device, adjust the gate voltage of the gate-sensing device.

10. A performance evaluation system for multi-junction photoelectric devices, characterized in that, A non-destructive comprehensive measurement and evaluation method for implementing the spatial service performance of a multi-junction photoelectric device as described in any one of claims 1 to 9, wherein the performance evaluation system for the multi-junction photoelectric device comprises: A quantum conversion characteristic measurement system, wherein the quantum conversion characteristic measurement system determines the optimal fluorescence wavelength of the selected PN junction based on the quantum transfer characteristics of the selected PN junction of the device; A fluorescence lifetime detection system, wherein the fluorescence lifetime detection system determines the fluorescence lifetime of the selected PN junction under periodic spatial irradiation at the optimal fluorescence wavelength of the selected PN junction; and A fitting system is used to determine the normalized power decay curve of the device based on the fluorescence lifetime of multiple PN junctions of the device, the current-voltage characteristics of the device, and the space irradiation type of the device.

11. The performance evaluation system for multi-junction photoelectric devices as described in claim 10, characterized in that, Also includes: An illumination device for providing a light source for the device; as well as An IV tester is used to obtain the current-voltage characteristics of the device.

Images