JP5900137B2 - Solar cell evaluation apparatus and method - Google Patents

Description

  The present invention relates to a solar cell evaluation apparatus and a solar cell evaluation method for evaluating a solar cell, and in particular, a solar cell that can appropriately evaluate a solar cell that requires time until a stable state is reached after the start of monochromatic light irradiation. The present invention relates to an evaluation apparatus and a solar cell evaluation method.

  A solar cell is an element that directly converts light energy into electric power by utilizing the photovoltaic effect, and various solar cells have been researched and developed, and have begun to spread widely in recent years. This solar cell (hereinafter abbreviated as “PV” as appropriate) includes silicon PV using silicon (Si), compound PV using a compound semiconductor such as InGaAs, and organic PV using an organic semiconductor. There are various types of organic PV, PN junction type PV that uses two types of organic semiconductors to form a PN junction and obtains photoelectromotive force by photoexcitation of electrons in the PN junction, and photoexcitation of electrons in organic dyes. And a dye-sensitized solar cell that obtains a photovoltaic power.

  Among such various solar cells, there is a solar cell that outputs an output current having a stable current value (substantially constant current value) immediately after irradiation with light, for example, represented by silicon PV. For example, as shown in FIGS. 8 and 9, represented by organic PV, the output current gradually increases with the passage of light irradiation time (transient state), and eventually becomes saturated and stable. There is a (steady state) solar cell.

  In order to properly evaluate such a solar cell that does not enter a steady state immediately after light irradiation, it is necessary to evaluate the solar cell in the steady state, and irradiation of white light called light soaking is performed. It is performed on the solar cell before the evaluation (for example, see Non-Patent Document 1 and Non-Patent Document 2).

  The light soaking effect is not lost immediately after the light soaking light irradiation is stopped, but is gradually lost as shown in FIG. For this reason, when light for evaluating the solar cell is irradiated after the light irradiation of the light soaking is stopped, the output current output from the solar cell gradually increases with time as shown in FIG. To drop.

  FIG. 8 is a diagram for explaining the effect of light soaking on the irradiation of white light, the horizontal axis is the elapsed time, and the vertical axis is the PV output current. FIG. 9 is a diagram showing actual measurement results for showing the effect of light soaking. The solid line shows the output current (mA), and the broken line shows the voltage (mV). The horizontal axis in FIG. 9 is the elapsed time, the vertical axis on the right side of the paper is the voltage, and the vertical axis on the left side of the paper is the current.

  The spectral sensitivity of a solar cell, which is one of the evaluation indexes for evaluating the performance of a solar cell, is the photoelectric conversion efficiency at each wavelength of incident light, and is usually expressed in units of A / W (ampere / watt). The Spectral sensitivity can be measured by irradiating the target solar cell with monochromatic light of the wavelength to be measured and dividing the output current of the solar cell by the energy of the monochromatic light irradiated. A phenomenon similar to that of light soaking is observed even when the monochromatic light irradiated to the solar cell is used to measure the spectral sensitivity. Therefore, the spectral sensitivity of the solar cell needs to be measured after it has stabilized after the start of monochromatic light irradiation.

"Dye-sensitized solar cell performance evaluation method", published by Japan Optical Industry Promotion Association, established in March 2009 Refer to 10.19.3 Procedure in “Thin-Film Thin Film Solar Cell (PV) Module-Requirements for Design Qualification Test and Type Certification”, JIS C 8991, 2011

  By the way, when evaluating a solar cell, determination of whether the solar cell is in the steady state is conventionally performed empirically. For example, the determination is performed by performing an evaluation process a plurality of times after starting a monochromatic light irradiation for spectral sensitivity measurement, and an operator determining whether or not the evaluation results are substantially equal. It has been broken. As a result, when each evaluation result is not substantially equal, various countermeasures such as a countermeasure for increasing the predetermined time after starting the monochromatic light irradiation are taken empirically.

  Thus, evaluation of the solar cell which will be in a steady state through a transient state is performed empirically, and it is difficult to guarantee the reliability of the evaluation result. Moreover, in order to obtain an evaluation result, it is necessary to perform the process a plurality of times, and it takes time to evaluate the solar cell.

  The present invention has been made in view of the above circumstances, and its object is to provide a solar cell that requires time until the output current is stabilized after starting monochromatic light irradiation with higher reliability and less effort. It is providing the solar cell evaluation apparatus and solar cell evaluation method which can be evaluated.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, the solar cell evaluation apparatus according to one aspect of the present invention receives an irradiation unit that irradiates irradiation light to the solar cell to be evaluated that requires irradiation with irradiation light for a predetermined time before the evaluation, and the irradiation light. Detection unit for detecting the output of the solar cell, a plurality of output values detected by the detection unit from the start of irradiation of the irradiation light by the irradiation unit, and the plurality of output values from the start of irradiation, respectively Is an output value measured by the detection unit when the irradiation of the irradiation light is continued using a function relating each elapsed time until the detection unit detects the change amount, An estimation unit that estimates an output value when it falls within a predetermined range and an evaluation unit that performs a predetermined evaluation based on the output value estimated by the estimation unit are provided.

  The solar cell evaluation apparatus having such a configuration starts irradiation of irradiation light and a plurality of output values detected by the detection unit when evaluating a solar cell that needs irradiation of irradiation light for a predetermined time before evaluation. Using the function that relates each elapsed time from when the output value is detected to when each output value is detected, the output value when the steady state is reached is estimated, and evaluation is performed based on the estimated output value . That is, it is possible to estimate the output value in the steady state only by detecting the output a plurality of times without waiting for the output of the solar cell to be in the steady state. Therefore, a solar cell that requires irradiation with irradiation light for a predetermined time before evaluation can be evaluated in a shorter time with high reliability, and can be evaluated with less effort.

  In another aspect, in the above-described solar cell evaluation apparatus, the irradiation light irradiated by the irradiation unit is monochromatic light having a predetermined wavelength, and the output value estimated by the estimation unit and the irradiation energy of the monochromatic light are Further, a spectral sensitivity calculation unit that calculates the spectral sensitivity of the predetermined wavelength based on the above is further provided.

  Since the solar cell evaluation apparatus having such a configuration can estimate the output current value in the steady state of the solar cell without waiting until the output of the solar cell reaches the steady state, the irradiation light for a predetermined time before the evaluation It is possible to obtain the spectral sensitivity of a solar cell that needs to be irradiated with high reliability in a shorter time.

  In another aspect, in the above solar cell evaluation device, the estimation unit further uses an irradiation duration time that is an elapsed time from the irradiation start time until the estimated output value is reached, using the function. It is characterized by calculating.

  The solar cell evaluation apparatus having such a configuration can estimate not only the steady state output of the solar cell but also the irradiation duration until the solar cell reaches the steady state. It is possible to estimate the irradiation duration only by detecting the output a plurality of times without waiting until it becomes.

  According to another aspect, in the above-described solar cell evaluation device, the irradiation unit can irradiate a plurality of monochromatic lights having different wavelengths as the irradiation light, and the estimation unit continues irradiation. The time is calculated for each of the plurality of monochromatic lights, and the spectral sensitivity calculation unit replaces the output value estimated by the estimation unit with the wavelength of the monochromatic light from the start of the monochromatic light irradiation by the irradiation unit. The spectral sensitivity is calculated using the output detected by the detection unit after the lapse of the irradiation duration calculated by the estimation unit.

  When the solar cell evaluation apparatus having such a configuration obtains the spectral sensitivity, which is the evaluation of a solar cell that requires irradiation with irradiation light for a predetermined time before the evaluation, a time corresponding to the wavelength of monochromatic light having a predetermined wavelength ( (Irradiation duration) After the irradiation, the output of the solar cell is detected, and the spectral sensitivity may be obtained based on the output. Therefore, it is possible to obtain the spectral sensitivity by monochromatic light for each wavelength in a state where the solar cell is in a steady state more reliably by setting the irradiation duration time that the spectral sensitivity with the accuracy desired by the user is obtained. In addition, it is possible to evaluate a solar cell that requires irradiation with irradiation light for a predetermined time before evaluation with higher reliability, and to perform evaluation with less effort.

  According to another aspect, in the solar cell evaluation device described above, the spectral sensitivity calculation unit is configured to irradiate the irradiation unit with monochromatic light having a wavelength different from the monochromatic light for which the evaluation unit has calculated the irradiation duration time. In this case, the wavelength of the monochromatic light to be irradiated based on the wavelength related to the wavelength of the monochromatic light to be irradiated and the irradiation duration of the wavelength among the wavelengths of the monochromatic light for which the evaluation unit has calculated the irradiation duration. And calculating the spectral sensitivity using the output detected by the detection unit after elapse of the calculated irradiation duration from the start of the irradiation of the monochromatic light by the irradiation unit. And

  Moreover, in another aspect, in the above-described solar cell evaluation device, the spectral sensitivity calculation unit includes the monochromatic light irradiated by the irradiation unit out of the wavelengths of the monochromatic light calculated by the evaluation unit. Based on the wavelength before and after the wavelength and the irradiation duration of the wavelength, the irradiation duration according to the wavelength of the monochromatic light to be irradiated is calculated by interpolation.

  Moreover, in another aspect, in the above-described solar cell evaluation device, the spectral sensitivity calculation unit includes the monochromatic light irradiated by the irradiation unit out of the wavelengths of the monochromatic light calculated by the evaluation unit. Based on the wavelength belonging to the wavelength range including the wavelength and the irradiation duration time of the wavelength, a relational expression between the wavelength and the irradiation duration time is obtained, and the irradiation duration time corresponding to the wavelength of the monochromatic light to be emitted is calculated by the relational expression. It is characterized by calculating.

  The solar cell evaluation apparatus having such a configuration obtains the irradiation duration based on the irradiation duration estimated by the estimation unit and its wavelength even when the estimation unit does not estimate the irradiation duration. Can do. Therefore, it is possible to obtain spectral sensitivity at a finer pitch than the wavelength pitch at which the estimation unit estimates the irradiation duration, and to perform evaluation with higher reliability with less effort.

  In another aspect, in the above-described solar cell evaluation apparatus, the irradiation unit can irradiate a plurality of monochromatic lights each having a different wavelength, and the spectral sensitivity calculation unit can be configured by the irradiation unit. Spectral sensitivity is calculated using the output detected by the detection unit after the elapse of a specific time from the start of monochromatic light irradiation, and the specific time is representative of the plurality of monochromatic lights emitted by the irradiation unit. The irradiation unit emits monochromatic light, and is the irradiation duration calculated by the estimation unit, and the representative monochromatic light is a monochromatic light having the longest wavelength among a plurality of monochromatic lights emitted by the irradiation unit. It is characterized by being.

In the solar cell evaluation apparatus having such a configuration, if the estimation unit uses a monochromatic light having a shorter wavelength than the wavelength for which the irradiation duration is estimated, the estimated irradiation duration is used to obtain the short wavelength monochromatic light. Since the spectral sensitivity can be accurately obtained, the evaluation can be performed with higher reliability with less effort.
Further, in another aspect, an irradiation unit that sequentially irradiates a plurality of monochromatic lights having different wavelengths as irradiation light to a solar cell to be evaluated that needs irradiation of irradiation light for a predetermined time before evaluation, A detection unit that detects an output of the solar cell when the plurality of monochromatic lights are sequentially irradiated by the irradiation unit, and a plurality of detection units detected from the start of irradiation of the monochromatic light by the irradiation unit. When the irradiation of the monochromatic light is continued using a function that relates the output value of each and the elapsed time from the start of irradiation to the time when the detection unit detects each of the plurality of output values. The output value measured by the detection unit, the output value when the amount of change is within a predetermined range is estimated, and further, the elapsed time from the start of irradiation until the estimated output value is reached The irradiation duration is calculated using the above function, The estimation unit that calculates each of the plurality of monochromatic lights, and the irradiation unit sequentially replaces the output value estimated by the estimation unit for each of the plurality of monochromatic lights irradiated by the irradiation unit. A spectral sensitivity calculation unit that calculates spectral sensitivity using the output detected by the detection unit after the lapse of the irradiation duration calculated by the estimation unit for the wavelength of the monochromatic light from the start of monochromatic light irradiation; It is characterized by.

  The solar cell evaluation apparatus and solar cell evaluation method according to the present invention can evaluate solar cells that require time until the output is stabilized after the start of monochromatic light irradiation with higher reliability and less effort.

It is a figure for demonstrating transition of the output current at the time of irradiating a monochromatic light to a solar cell. It is a figure for demonstrating the measurement point of the output current of a solar cell. It is a figure which shows the timing of switching of the monochromatic light to irradiate. It is a figure which shows the structure of the solar cell evaluation apparatus of the solar cell in embodiment. It is a flowchart which shows the spectral sensitivity measurement process of the solar cell of a solar cell evaluation apparatus. It is a flowchart which shows the modification 1 of the spectral sensitivity measurement process of a solar cell evaluation apparatus. It is a flowchart which shows the modification 2 of the spectral sensitivity measurement process of a solar cell evaluation apparatus. It is a figure for demonstrating the effect of the light soaking with respect to irradiation of white light. It is a figure which shows the actual measurement result for showing the effect of light soaking.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
<Embodiment>
The solar cell evaluation apparatus for a solar cell in the embodiment measures spectral sensitivity as an evaluation index for evaluating the performance of the solar cell, and shortens the time required for measuring the spectral sensitivity of the solar cell.

  FIG. 1 is a diagram for explaining the transition of the output current when the solar cell PV is irradiated with monochromatic light, the horizontal axis is the elapsed time, and the vertical axis is the output current of the solar cell PV. is there.

  The graph α1 is a graph showing the transition of the output current when the solar cell PV is irradiated with monochromatic light having a wavelength of 450 nm (nanometers), and the graph α2 is a monochromatic light having a wavelength of 700 nm. It is a graph which shows transition of an output current when it irradiates to. In FIG. 1, time t10 indicates the time when monochromatic light irradiation is started, and time t11 indicates the time when the output current is in a steady state when monochromatic light having a wavelength of 450 nm is irradiated. The time t12 indicates the time when the output current is in a steady state when monochromatic light with a wavelength of 700 nm is irradiated.

  As shown in FIG. 1, the output current of the solar cell PV gradually increases with the elapse of the monochromatic light irradiation time, and eventually becomes saturated and becomes a stable current value (steady state). In addition, the time until the steady state varies depending on the wavelength of the monochromatic light. That is, the rising curve of the output current until it reaches a steady state varies depending on the wavelength of light irradiated on the solar cell.

  In the solar cell evaluation apparatus of the embodiment, the change in the output current of the solar cell PV is applied to the model formula to predict the output current in the steady state. Therefore, the output current in the steady state can be predicted only by measuring the output current for the number of times that the constant of the model formula can be determined. That is, since it is not necessary to irradiate with monochromatic light until the steady state is reached, the spectral sensitivity measurement time can be greatly shortened. Further, by changing the number of output current measurements and the measurement interval, the spectral sensitivity can be obtained with the reliability desired by the user. Further, from the model formula, it is also possible to predict the time (irradiation duration) from when the monochromatic light irradiation is started until the output current becomes a steady state. Hereinafter, the time from when the monochromatic light irradiation is started until the output current reaches a steady state is referred to as “waiting time after starting monochromatic light irradiation”.

  FIG. 2 is a diagram for explaining the measurement points of the output current of the solar cell, the horizontal axis is the elapsed time, and the vertical axis is the output current of the solar cell PV. The broken line graph is a graph showing the transition of the output current when a certain monochromatic light is applied to the solar cell. Time t20 indicates the time when monochromatic light irradiation is started, and time t26 indicates the time when the output current is in a steady state. Each of the times t21, t22, t23, t24, and t25 indicates the time when the output current is measured, and the black rectangle indicates the measurement point for each time.

  For example, the measurement results at five measurement points from time t21 to t25, specifically, the elapsed time from time t20 for each of time t21 to time t25 and the output current value at each time from time t21 to time t25 By creating the relational expression, the steady-state output current I20 can be estimated at the time t25. Therefore, it is possible to stop the irradiation of monochromatic light immediately after time t25. In the embodiment, the measurement is terminated when the output current is measured five times. However, the measurement termination condition may be other conditions. For example, the number of times may not be five, and the number of times of measurement may be changed for each monochromatic light. Moreover, it is good also considering the time to measure as completion | finish conditions. For example, measurement is performed at a predetermined interval for 10 seconds from the start of irradiation. Furthermore, measurement may be performed until the output current reaches a predetermined current value.

  FIG. 3 is a diagram showing the timing of switching of the monochromatic light to be irradiated, the horizontal axis is the elapsed time, and the vertical axis is the output current of the solar cell PV. Graphs α3, α4, and α5 are monochromatic lights having different wavelengths, and are graphs showing changes in output current when monochromatic lights having wavelengths λ3, λ4, and λ5 are irradiated to the solar cell PV, respectively. The output current is measured at five measurement points at wavelengths λ3, λ4, and λ5, respectively.

  The time t30 indicates the time when the irradiation of the monochromatic light having the wavelength λ3 is started, and the time t31 indicates the time when the irradiation of the monochromatic light having the wavelength λ4 is started. At time t31, the output current of the solar cell is not in a steady state due to the irradiation of the monochromatic light of wavelength λ3, but the steady state output current value using the relational expression created from the measurement result at the measurement point Can be predicted. Similarly, at the time t32 when the monochromatic light of the wavelength λ5 starts, the steady state output current can be predicted although the steady state is not reached by the irradiation of the monochromatic light of the wavelength λ4. Thus, the irradiation time of a plurality of monochromatic lights can be shortened.

  In the solar cell evaluation apparatus of the embodiment, it is possible to start the next monochromatic light irradiation after the measurement of the output current is completed five times without waiting for the output current to reach a steady state.

  In other words, the spectral sensitivity can be obtained by predicting the output current in the steady state without performing monochromatic light irradiation until the steady state is reached. Can be obtained.

In addition, in FIG.2 and FIG.3, the case where the output current of the steady state of the solar cell PV was estimated by irradiating monochromatic light and calculating | requiring the relational expression of elapsed time and an output electric current value for every monochromatic light was demonstrated. However, in addition to monochromatic light, for example, white light approximated to natural sunlight (for example, sunlight of AM 1.5 at 1000 W / m ² ), or light from indoor lighting such as fluorescent lamps, white LEDs, and tungsten lamps. It is also possible to estimate the steady-state output current value of the solar cell PV and the waiting time after the start of irradiation of these lights when irradiated. In the embodiment, monochromatic light will be described.

<Configuration>
Drawing 3 is a figure showing the composition of the solar cell evaluation device of the solar cell in an embodiment. The solar cell evaluation apparatus S for solar cells in the embodiment is an apparatus that evaluates a solar cell PV to be evaluated, which requires a waiting time after the start of monochromatic light irradiation, using a predetermined evaluation item. For example, as shown in FIG. Furthermore, the evaluation light irradiation unit 1, the optical system 2, the detection unit 3, the calculation control unit 4, the input unit 5, the output unit 6, the interface (IF) unit 7, and the storage unit 8 are provided.

  The evaluation light irradiating unit 1 is an apparatus that irradiates evaluation light for performing evaluation on the predetermined evaluation item according to the control of the arithmetic control unit 4. In the present embodiment, since the predetermined evaluation item is the spectral sensitivity of the solar cell, the evaluation light is monochromatic light whose irradiation light energy is known, and the wavelength of the monochromatic light needs to be variable. The variable wavelength band of the monochromatic light includes a wavelength range in which the solar cell PV to be evaluated has sensitivity. For this reason, the evaluation light irradiating unit 1 selects (varies) the wavelength of the monochromatic light, adjusts the emitted light intensity of the monochromatic light, and turns on the monochromatic light according to the control of the arithmetic control unit 4. It is a device having various functions such as a function to turn off. The evaluation light irradiation unit 1 for evaluating with such spectral sensitivity includes, for example, an evaluation light source drive control unit 11, an evaluation light source unit 12, an optical system 13, and a monochromator 14, as shown in FIG. And an optical system 15, a branching optical coupler unit 16, an irradiance detection unit 17, and an amplification unit 18.

  The evaluation light source unit 12 is a light source device that emits light in a predetermined wavelength band including the wavelength of monochromatic light emitted from the monochromator 14, and is, for example, a xenon lamp. Xenon lamps are suitable for measuring spectral sensitivity because they have high brightness and color temperature and emit light in a continuous spectrum over a wide band from ultraviolet to visible to infrared. The evaluation light source drive control unit 11 performs evaluation light such as drive control of emission (lighting) and stop (lighting off) of the evaluation light and adjustment control of the intensity of emitted light of the evaluation light according to the control of the arithmetic control unit 4. It is a device that drives and controls the light source unit 12.

  The optical system 13, the optical system 15, and the optical system 2 are optical elements such as lenses for concentrating or collimating (collimating) light according to the application. The light emitted from the evaluation light source unit 12 according to the control of the evaluation light source drive control unit 11 enters the monochromator 14 via the optical system 13.

  The monochromator 14 converts the light incident from the evaluation light source 12 through the optical system 13 into monochromatic light at a predetermined wavelength according to the instruction (selection) of the arithmetic control unit 4 according to the control of the arithmetic control unit 4. It is a device that injects. The monochromator 14 is, for example, a spectroscope that spatially disperses the light in the predetermined wavelength band and extracts only a narrow range of wavelengths with a slit or the like. Such a monochromator 14 includes, for example, an entrance slit, a first reflecting mirror, a diffraction grating, a second reflecting mirror, and an exit slit, and an incident light beam incident through the entrance slit is transferred to the diffraction grating by the first reflecting mirror. This is a device that reflects the diffracted light of the incident light beam reflected and diffracted by the diffraction grating to the exit slit by the second reflecting mirror. With such a configuration, the monochromator 14 can select the wavelength of light that reaches the slit position by rotating the diffraction grating or the like, and can extract only a wavelength in a desired range (single-color light conversion). The monochromator 14 is controlled by the arithmetic control unit 4 so as to extract the wavelength in the desired range. The monochromatic light emitted from the monochromator 14 is incident on the branch optical coupler unit 16 through the optical system 15.

  The branching optical coupler unit 16 is an optical component that divides incident light into two lights and emits them. The monochromatic light incident on the branching optical coupler unit 16 is distributed by the branching optical coupler unit 16, one of which is incident on the irradiance detection unit 17, and the other is the sun to be evaluated via the optical system 2. The battery PV is irradiated.

  The irradiance detector 17 is a device (reference detector) that measures the irradiance (not the spectral irradiance) of monochromatic light (monochromatic light emitted from the monochromator 14) distributed by the branching optical coupler unit 16. The measurement result is output to the amplifying unit 18. The amplifying unit 18 amplifies the irradiance measured by the irradiance detecting unit 17 with a predetermined amplification factor and outputs the amplified irradiance to the arithmetic control unit 4. When the irradiance of monochromatic light is known by measuring in advance, the irradiance detection unit 17, the amplification unit 18 and the branching optical coupler unit 16 may be omitted.

  The detection part 3 is an apparatus which detects the output of the said solar cell PV according to an evaluation item. In this embodiment, since the predetermined evaluation item is the spectral sensitivity of the solar cell, the detection unit 3 is a device that can understand the voltage and current of the solar cell PV. More specifically, the detection unit 3 can measure the output current of the solar cell PV by applying a voltage having a predetermined voltage value to the solar cell PV according to the control of the arithmetic control unit 4. This is a so-called source meter capable of changing the predetermined voltage value. The detection unit 3 outputs the output of the solar cell detected at a predetermined sampling interval to the calculation control unit 4.

  The input unit 5 is a device for inputting commands (commands), data, and the like from the outside to the solar cell evaluation apparatus S, and is, for example, a keyboard, a mouse, a touch panel, or the like.

  The output unit 6 is a device for outputting commands and data input from the input unit 5 and the calculation result of the calculation control unit 4. For example, the output unit 6 is a display device such as an LCD (liquid crystal display) or an organic EL display, A printing apparatus such as a printer.

  The IF unit 7 is a communication interface for exchanging data between the solar cell evaluation device S and other external devices. For example, the IF unit 7 conforms to a USB (Universal Serial Bus) standard or an RS232C standard. It is a corresponding device.

  The storage unit 8 is an external storage device such as a hard disk device, for example, and stores, for example, detection results of the detection unit 3, programs and data necessary for operation of the calculation control unit 4, calculation results of the calculation control unit 4, and the like. It is.

  In the embodiment, the storage unit 8 includes, as data necessary for spectral sensitivity measurement processing, the entire wavelength range to be measured, the wavelength pitch to be measured, and the timing for measuring the output current (hereinafter referred to as “measurement timing”). The irradiation area A of the solar cell PV is stored. For example, 300 to 1200 nm is stored as the entire wavelength range to be measured, and 5 nm is stored as the pitch. In this case, the number of monochromatic lights to be measured is 181. As the measurement timing, five elapsed times from the start of monochromatic light irradiation are stored. Further, the measured spectral sensitivity is stored in the storage unit 8.

  The total wavelength range to be measured, the pitch of the wavelength to be measured, the timing to measure the output current, and the irradiation area A of the solar cell PV are stored before the evaluation process of the solar cell PV is started. When the irradiance of each monochromatic light is measured and stored in advance, the measured irradiance is also stored before the spectral sensitivity measurement process is started.

  The arithmetic and control unit 4 is an apparatus that controls the entire operation of the solar cell evaluation device S by controlling each unit according to the function, and calculates the evaluation of the solar cell PV. The arithmetic control unit 4 includes, for example, a microprocessor including a CPU (Central Processing Unit), a storage element such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and peripheral circuits thereof. Etc.

  The arithmetic control unit 4 is functionally configured with a spectral sensitivity calculation unit 41 and a current estimation unit 42 by executing a program.

  The spectral sensitivity calculation unit 41 includes the current value dI passed from the arithmetic control unit 4, the irradiance dE per unit area calculated from the irradiance output from the amplification unit 18, and the sun stored in the storage unit 8. Spectral sensitivity S (I, λ) = dI (λ) × A / dE (λ) is calculated from the irradiation area A of the monochromatic light irradiated to the battery PV.

  The current estimation unit 42 determines the constant of the model formula when the calculation control unit 4 is passed the time of the measurement timing and the current value, and calculates the steady state output current of the solar cell from the model formula. The function of returning the calculated current value to the arithmetic control unit 4 is provided. The steady-state output current calculated here is when the waiting time after the start of monochromatic light irradiation ends and the change in the output current with the passage of time becomes almost zero, in other words, the amount of change is a predetermined threshold value. It corresponds to the output current when The time of the measurement timing passed from the arithmetic control unit 4 is an elapsed time from the start of monochromatic light irradiation, and the current value is the current value output by the detection unit 3 at the measurement timing.

The current estimation unit 42 stores an asymptotic expression as a model expression, and stores, for example, one of the following expressions.
I = A × exp (−B / t) (Formula 1)
I = A−B / t (Formula 2)
I = A × sin (t / T) (Formula 3)
In Equations 1 to 3, I represents the output current value, t represents the elapsed time, and A and B are constants that characterize the function. In Equation 3, T is a time constant.

  The current estimation unit 42 determines A and B in the case of Expression 1 and Expression 2 from a plurality of sets of the elapsed time t and the current value I passed from the arithmetic control unit 4, and in the case of Expression 3, A and T are determined, a current value I when t is infinite is obtained, and the obtained current value I is estimated as an output current value in a steady state.

  The model formula may be a relational formula other than the above, or a plurality of model formulas may be stored. When a plurality of data are stored, for example, the user may select which formula to use via the input unit 5.

  Moreover, it is good also as using a measurement result instead of a model type | formula. For example, for the first wavelength, the waiting time after the start of monochromatic light irradiation from when the monochromatic light is irradiated until the output current of the solar cell PV reaches a steady state is measured. In the next monochromatic light, the steady-state output current value of the monochromatic light is estimated by multiplying the coefficient based on the change in the measured value of the first monochromatic light. The coefficient is determined in advance by measuring other solar cells PV, similar solar cells PV, or the like. According to this method, as shown by the graph α1 and the graph α2 in FIG. 2, estimation with a small error is possible even for a solar cell in which the output current stabilization time varies depending on the monochromatic light.

  When the number of constants to be determined is two, the steady-state output current can be estimated with two measurements from the start of irradiation. However, in general, measurement of output current includes measurement errors due to the accuracy of the measuring instrument and noise components, and estimation from a small number of measurement values is likely to cause a large error. Therefore, in order to reduce the error, it is desirable to determine the constant by a method such as least square approximation based on the measurement results of a plurality of times.

  The arithmetic control unit 4 controls the evaluation light source drive control unit 11 and the monochromator 14 to sequentially irradiate monochromatic light for each pitch stored in the storage unit 8, and causes the spectral sensitivity calculation unit 41 to perform spectral spectroscopy for each monochromatic light. The sensitivity is calculated, and the calculated spectral sensitivity is stored in the storage unit 8. The spectral sensitivity for each monochromatic light is obtained by the calculation control unit 4 acquiring the output of the detection unit 3 at each measurement timing (elapsed time) stored in the storage unit 8, and the current estimation unit 42 outputs the output current in the steady state. It is obtained by estimating the value, passing the estimated output current value to the spectral sensitivity calculation unit 41, and calculating the spectral sensitivity. Note that the arithmetic control unit 4 has a timer, and has a function of measuring the elapsed time from the start of irradiation and detecting the measurement timing.

<Operation>
Next, operation | movement of the solar cell evaluation apparatus S of embodiment is demonstrated. FIG. 5 is a flowchart of a process for evaluating the solar cell PV, that is, a spectral sensitivity measurement process.

  When the operator (user) places the solar cell PV to be evaluated at a predetermined position (step S10) and receives an instruction to start measurement of the first solar cell PV from the input unit 5, the arithmetic control unit 4 To start operation. Thereafter, the arithmetic control unit 4 reads out the entire wavelength range to be measured and the pitch of the wavelength to be measured from the storage unit 8, and the evaluation light source drive control unit 11 so that the evaluation light source unit 12 emits monochromatic light of the first wavelength. The monochromator 14 is controlled (step S11), and the start of monochromatic light irradiation is instructed (step S12). The first monochromatic light to be irradiated is assumed to irradiate monochromatic light having the shortest wavelength in the entire wavelength range to be measured, and sequentially irradiate monochromatic light having a wavelength shifted by the pitch in the long wavelength direction. . In addition, it is good also as irradiating sequentially the monochromatic light of the wavelength shifted | deviated by the pitch from the long wavelength to the short wavelength, and you may determine the order of the monochromatic light to irradiate at random.

  The calculation control unit 4 that has instructed the start of monochromatic light irradiation starts measurement of the elapsed time from the start of irradiation, and when the measurement timing stored in the storage unit 8 comes, the output of the solar cell PV is output at a predetermined sampling interval. The most recently detected output current of the solar cell PV is acquired from the detection unit 3 that detects the current, and stored in the storage unit 8 (step S13).

  The calculation control unit 4 that has acquired the output current from the detection unit 3 determines whether the output current of the solar cell PV has been acquired from the detection unit 3 at all measurement timings, in the embodiment, at five measurement timings (step S14). ) If not acquired (step S14: No), the elapsed time is continuously measured until the next measurement timing. When it is determined that the output current has been acquired at all five measurement timings (step S14: Yes), the calculation control unit 4 determines the measurement timing (elapsed time) and the output current acquired from the detection unit 3 at each measurement timing. The value is passed to the current estimation unit 42 to request calculation of the output current value in the steady state.

  Upon receiving the request, the current estimation unit 42 determines a constant of the model formula from the passed elapsed time and current value (step S15), and calculates (estimates) the output current value in the steady state (step S16). . The current estimation unit 42 returns the calculated output current value to the calculation control unit 4.

  The arithmetic control unit 4 that has received the output current value passes the received output current value to the spectral sensitivity calculation unit 41 and requests calculation of the spectral sensitivity.

  Upon receiving the request, the spectral sensitivity calculation unit 41 obtains the current value dI passed from the calculation control unit 4 and the irradiance from the amplification unit 18 to calculate the irradiance dE per unit area. The irradiation area A of the battery PV is read, and the spectral sensitivity S (I, λ) = dI (λ) × A / dE (λ) is calculated and passed to the arithmetic control unit 4 (step S17).

  Receiving the spectral sensitivity from the spectral sensitivity calculation unit 41, the calculation control unit 4 stores the spectral sensitivity in the storage unit 8 in association with the irradiating monochromatic light (step S18).

  The arithmetic control unit 4 having the spectral sensitivity stored in the storage unit 8 determines whether or not the spectral sensitivity has been measured for all the monochromatic lights for all the wavelengths to be measured (step S19). If it is determined that measurement has not been performed for all monochromatic lights (step S19: No), the arithmetic control unit 4 performs the processing from step S11 to step S19 for all monochromatic lights.

  When it is determined that the spectral sensitivities have been measured for all the monochromatic lights for all wavelengths to be measured (step S19: Yes), the arithmetic control unit 4 reads out and reads the spectral sensitivities of all the monochromatic lights from the storage unit 8. That the spectral sensitivity and the measurement of the spectral sensitivity are completed are displayed on the output unit 6 (step S20), and the process is terminated.

  In the solar cell evaluation apparatus S as described above, it is possible to save time and effort for determining the waiting time until the output current of the solar cell PV reaches a steady state by trial and error, and the output current for each monochromatic light. Therefore, it is only necessary to irradiate until it can be estimated, so that it is possible to perform a quick measurement while minimizing unnecessary waiting time in the measurement of spectral sensitivity.

<Modification 1>
In the embodiment, the output current in a stable state of the solar battery PV is estimated for each monochromatic light from the model formula. In Modification 1, the time until the output current becomes stable is estimated for each monochromatic light. In the first modification, a case where the estimated time for each monochromatic light is stored and used for the spectral sensitivity measurement process of the solar cell PV of the same type as the solar cell PV whose time is estimated will be described.

  In the spectral sensitivity measurement process of the same type of solar cell PV, the spectral sensitivity can be obtained by measuring the output current after irradiation for a stored time without using a model formula, etc. It is possible to measure the spectral sensitivity.

  The configuration of the solar cell evaluation apparatus S of Modification 1 is the same as the configuration shown in FIG. 4, but the following processing is performed in addition to the spectral sensitivity measurement processing described using the flowchart of FIG.

  In step S16 of FIG. 5, in addition to estimating the output current, the current estimation unit 42 estimates the irradiation time (waiting time after starting monochromatic light irradiation) until the steady state is reached, and performs the current irradiation. It is stored in the storage unit 8 in association with the wavelength of the monochromatic light. For example, in step S16, the current value I when t in Equation (1) above is set to infinity is obtained, and the absolute value of the difference between the obtained current value I and the model formula is equal to or less than a predetermined threshold value. The shortest elapsed time is defined as a stabilization waiting time (waiting time after starting monochromatic light irradiation). For example, in the case of Equation 2, the minimum elapsed time t at | I20− (AB / t) | ≦ T is the stabilization waiting time. T is a predetermined threshold and is a value close to 0.

  In FIG. 2, the time from time t20 to time t26 is the stabilization waiting time. This stabilization waiting time may be adjusted according to the accuracy of spectral sensitivity desired by the user. For example, when more accuracy is required, the stabilization waiting time is set longer.

  By performing this process, the solar cell evaluation apparatus S obtains the spectral sensitivity by estimating the steady-state output current of the solar cell PV, and at the same time after the start of monochromatic light irradiation until the steady state for each monochromatic light. The waiting time is estimated and stored.

  Next, using FIG. 6, the spectral sensitivity measurement process of the solar cell PV of the same type as the solar cell PV (hereinafter referred to as “first solar cell PV”) whose waiting time after the start of monochromatic light irradiation is estimated. That is, the spectral sensitivity measurement process using the waiting time after the start of monochromatic light irradiation will be described.

  When the solar cell PV to be evaluated is placed at a predetermined position by the operator (user) (step S20) and an instruction to start measurement of the solar cell PV using the waiting time after the start of monochromatic light irradiation is received from the input unit 5, The arithmetic control unit 4 instructs each functional unit to start operation. Thereafter, the arithmetic control unit 4 reads out the entire wavelength range to be measured, the pitch of the wavelength to be measured, and the waiting time after the start of monochromatic light irradiation stored in association with each monochromatic light from the storage unit 8, The evaluation light source drive control unit 11 and the monochromator 14 are controlled so that the evaluation light source unit 12 emits monochromatic light of the wavelength (step S21), and the start of monochromatic light irradiation is instructed (step S22). It is desirable that the order of monochromatic light to be irradiated is the same as that in the measurement of the first solar cell PV. Specifically, in the measurement process of the first solar cell PV, when the monochromatic light of the wavelength shifted by the pitch in the direction of the long wavelength from the shortest wavelength among all the wavelength ranges to be measured is sequentially irradiated, from the short wavelength The monochromatic light is irradiated in order by shifting the pitch. This is because the monochromatic light previously irradiated produces a hysteresis effect and the monochromatic light stabilization waiting time has wavelength dependency.

  The calculation control unit 4 instructing the start of monochromatic light irradiation reads the waiting time after the start of monochromatic light irradiation stored in the storage unit 8 in association with the emitted monochromatic light, and starts counting time (step S23). : No), when the waiting time after the start of monochromatic light irradiation has elapsed (step S23: Yes), the spectral sensitivity calculation unit 41 is requested to calculate the spectral sensitivity. For example, in FIG. 3, when the irradiation of the monochromatic light with the wavelength λ3 is started at time t30, the spectral sensitivity calculation unit 41 is requested to calculate the spectral sensitivity at time t31. Similarly, when the irradiation of the monochromatic light of wavelength λ4 is started at time t31, the spectral sensitivity calculation unit 41 is requested to calculate the spectral sensitivity at time t32.

  Upon receiving the request, the spectral sensitivity calculation unit 41 obtains the irradiance from the amplification unit 18 to calculate the irradiance dE per unit area, reads the irradiation area A of the solar cell PV from the storage unit 8, and from the detection unit 3. The current value dI is acquired (step S24), the spectral sensitivity S (I, λ) = dI (λ) × A / dE (λ) is calculated and passed to the arithmetic control unit 4 (step S25).

  Receiving the spectral sensitivity from the spectral sensitivity calculation unit 41, the calculation control unit 4 stores the spectral sensitivity of the solar cell PV currently being measured in the storage unit 8 in association with the irradiating monochromatic light (step S26).

  The arithmetic control unit 4 having the spectral sensitivity stored in the storage unit 8 determines whether or not the spectral sensitivity has been measured for all the monochromatic lights for all the wavelengths to be measured (step S27). If it is determined that measurement has not been performed for all monochromatic lights (step S27: No), the arithmetic control unit 4 performs the processing from step S21 to step S27 for all monochromatic lights.

  When it is determined that the spectral sensitivities have been measured for all the monochromatic lights for all wavelengths to be measured (step S27: Yes), the arithmetic control unit 4 reads out and reads the spectral sensitivities of all the monochromatic lights from the storage unit 8. The spectral sensitivity and the fact that the measurement of spectral sensitivity has been completed are displayed on the output unit 6 (step S28), and the process is terminated.

  By the above processing, it is possible to easily obtain the spectral sensitivity of the solar cell PV of the same type as the solar cell PV whose time has been estimated.

  In the solar cell evaluation apparatus S of Modification 1, all the monochromatic light model equations for each pitch are created and the waiting time after the start of monochromatic light irradiation is calculated. Calculate and store the waiting time after the start of monochromatic light irradiation, and based on this wavelength and the waiting time after the start of monochromatic light irradiation, the monochromatic light irradiation of monochromatic light for which no model formula has been created The waiting time after the start may be calculated. For example, the waiting time after the start of monochromatic light irradiation of monochromatic light having a single pitch wavelength is obtained from the model formula, and the waiting time after the start of monochromatic light irradiation of the monochromatic light having the skipped wavelength is determined as the wavelength before and after the monochromatic light. It is good also as calculating by interpolation (for example, linear interpolation) from the waiting time after the monochromatic light irradiation start of this monochromatic light. When the pitches are equal, the waiting time after the start of monochromatic light irradiation of monochromatic light of the front and rear wavelengths may be added and divided by two. If the pitches are not equal, the weighted average is determined by the wavelength interval. Moreover, it is good also as calculating | requiring the waiting time after the start of monochromatic light irradiation of the monochromatic light of the skipped wavelength from the relational expression by calculating | requiring the waiting time after the monochromatic light irradiation start calculated | required from the model formula, and its wavelength. . For example, the relational expression is obtained from the wavelength measured within the wavelength range including the skipped wavelength and the waiting time after the start of the monochromatic light irradiation. In addition, the wavelength range including the skipped wavelength includes only wavelengths shorter than the skipped wavelength, includes only wavelengths longer than the skipped wavelength, and includes wavelengths shorter and longer than the skipped wavelengths. The wavelength of the wavelength may be included.

<Modification 2>
In the first modification, the waiting time after starting monochromatic light irradiation is estimated for all the monochromatic lights for every pitch in the entire wavelength range to be measured, and the waiting time after starting monochromatic light irradiation is changed for each monochromatic light. Spectral sensitivity was measured.

  In the second modification, a case will be described in which all wavelengths are divided into a plurality of blocks so as to include a plurality of monochromatic lights to be measured, and one monochromatic light irradiation start time is used for each block. Blocking is performed by making monochromatic light into a single block whose waiting time after the start of monochromatic light irradiation falls within a predetermined time range. For example, when the predetermined time range is 3 to 6 seconds, the wavelength of the monochromatic light whose waiting time after starting the monochromatic light irradiation is longer than 3 seconds and shorter than 6 seconds belongs to one block. Become.

  FIG. 7 is a flowchart of processing for obtaining the waiting time after starting the monochromatic light irradiation of the solar cell PV and measuring the spectral sensitivity. The solar cell PV of the same type as this solar cell PV (first solar cell PV) is irradiated with a waiting time after the start of monochromatic light irradiation for each monochromatic light in the same manner as the processing described with reference to FIG. Will be calculated. However, the difference from FIG. 6 is that the waiting time after the start of monochromatic light irradiation is different for each block, not for each monochromatic light.

  Hereinafter, the spectral sensitivity measurement process will be described with reference to the flowchart of FIG.

  When the operator (user) places the solar cell PV to be evaluated at a predetermined position (step S30) and receives an instruction to start measurement of the first solar cell PV from the input unit 5, the arithmetic control unit 4 To start operation. Thereafter, the calculation control unit 4 reads out the entire wavelength range to be measured and the pitch of the wavelength to be measured from the storage unit 8, and divides the entire wavelength range into a plurality of blocks (step S31). In the embodiment, it is assumed that the monochromatic light belonging to the block has a continuous wavelength. The user may perform block division via the input unit 5 and the output unit 6.

  The calculation control unit 4 divided into blocks controls the evaluation light source drive control unit 11 and the monochromator 14 so that the evaluation light source unit 12 emits representative single color light among a plurality of single color lights constituting the first block. Then, the start of monochromatic light irradiation is instructed (step S32). In the embodiment, the representative monochromatic light is the monochromatic light having the longest wavelength among the monochromatic lights constituting the block. This is because, in general, it takes longer for the output current of the solar cell PV to reach a steady state when the long wavelength monochromatic light is irradiated than when the short wavelength monochromatic light is irradiated.

  The calculation control unit 4 that has instructed the start of monochromatic light irradiation starts measurement of the elapsed time from the start of irradiation, and when the measurement timing stored in the storage unit 8 comes, the output of the solar cell PV is output at a predetermined sampling interval. The most recently detected output current of the solar cell PV is acquired from the detection unit 3 that detects the current, and is stored in the storage unit 8 (step S33).

  The calculation control unit 4 that has acquired the output current from the detection unit 3 determines whether the output current of the solar cell PV has been acquired from the detection unit 3 at all measurement timings, in the embodiment, at five measurement timings (step S34). ) If not acquired (step S34: No), the measurement of the elapsed time is continued until the next measurement timing. When it is determined that the output current has been acquired at all five measurement timings (step S34: Yes), the arithmetic control unit 4 determines the measurement timing (elapsed time) and the output current acquired from the detection unit 3 at each measurement timing. The value is passed to the current estimation unit 42 to request calculation of the output current value in the steady state and the waiting time after the start of monochromatic light irradiation.

  Upon receiving the request, the current estimation unit 42 determines the constant of the model formula from the passed elapsed time and current value (step S35), and waits for the output current value in the steady state and after the start of monochromatic light irradiation. Time is calculated (estimated) (step S36). The current estimation unit 42 returns the calculated output current value and the waiting time after the start of monochromatic light irradiation to the arithmetic control unit 4.

  The arithmetic control unit 4 that has received the output current value and the waiting time after starting the monochromatic light irradiation associates the received waiting time after starting the monochromatic light irradiation with the block to which the irradiating monochromatic light belongs, and stores the unit 8 (step S37). The arithmetic control unit 4 passes the received output current value to the spectral sensitivity calculation unit 41 and requests calculation of the spectral sensitivity.

  Upon receiving the request, the spectral sensitivity calculation unit 41 obtains the current value dI passed from the calculation control unit 4 and the irradiance from the amplification unit 18 to calculate the irradiance dE per unit area. The irradiation area A of the battery PV is read out, and the spectral sensitivity S (I, λ) = dI (λ) × A / dE (λ) is calculated and passed to the arithmetic control unit 4 (step S38).

  The calculation control unit 4 that has received the spectral sensitivity from the spectral sensitivity calculation unit 41 stores it in the storage unit 8 in association with the irradiating monochromatic light (step S39).

  Next, the calculation control unit 4 controls the evaluation light source drive control unit 11 and the monochromator 14 so that the evaluation light source unit 12 irradiates the monochromatic light that has not yet been measured in the block (step S40), and the monochromatic light. Is started (step S41).

  The calculation control unit 4 that has instructed the start of monochromatic light irradiation stores the waiting time after the start of monochromatic light irradiation stored in the storage unit 8 in association with the block to which the monochromatic light being illuminated belongs, that is, stored in step S37. The counting of the waiting time after starting the monochromatic light irradiation stored in the unit 8 is started (step S42: No), and when the waiting time after starting the monochromatic light irradiation has elapsed (step S42: Yes), the spectral sensitivity calculating unit 41 performs spectroscopic analysis. Request calculation of sensitivity.

  Upon receiving the request, the spectral sensitivity calculation unit 41 obtains the irradiance from the amplification unit 18 to calculate the irradiance dE per unit area, reads the irradiation area A of the solar cell PV from the storage unit 8, and from the detection unit 3. The current value dI is acquired (step S41), the spectral sensitivity S (I, λ) = dI (λ) × A / dE (λ) is calculated and passed to the arithmetic control unit 4 (step S44).

  Receiving the spectral sensitivity from the spectral sensitivity calculation unit 41, the calculation control unit 4 stores the spectral sensitivity of the solar cell PV currently being measured in the storage unit 8 in association with the irradiating monochromatic light (step S45).

  The calculation control unit 4 having the spectral sensitivity stored in the storage unit 8 determines whether or not the spectral sensitivity has been measured for the monochromatic light belonging to the block (step S46). If it is determined that measurement has not been performed for all monochromatic lights (step S46: No), the arithmetic control unit 4 performs the processing from step S40 to step S46 for all monochromatic lights belonging to the block.

  When it is determined that the spectral sensitivity has been measured for all the monochromatic lights in the block (step S46: Yes), the arithmetic control unit 4 measures the spectral sensitivity for all the wavelengths to be measured, that is, for the monochromatic light of all the blocks. It is determined whether or not the process is over (step S47). If it is determined that measurement has not been performed for all blocks (step S47: No), the arithmetic control unit 4 performs the processing from step S32 to step S47 for all blocks.

  When it is determined that the spectral sensitivities have been measured for all the monochromatic lights for all blocks (step S47: Yes), the arithmetic control unit 4 reads the spectral sensitivities of all the monochromatic lights from the storage unit 8, and reads the spectral sensitivities. The fact that the measurement of the spectral sensitivity is completed is displayed on the output unit 6 (step S48), and the process is terminated.

  In the solar cell evaluation apparatus S of Modification 2, monochromatic light having a short wavelength has a small difference in waiting time after the start of monochromatic light irradiation until it reaches a steady state, and thus a plurality of monochromatic lights are collectively blocked. This makes it possible to perform efficient spectral sensitivity measurement.

  In the modified example 1, the waiting time after the start of monochromatic light irradiation is estimated for each monochromatic light, and in the modified example 2, the waiting time after the start of monochromatic light irradiation is estimated for each block. You may measure all monochromatic light using the waiting time after a start. Although the waiting time after the start of monochromatic light irradiation for each monochromatic light is not the shortest, the time required to determine the waiting time after the start of monochromatic light irradiation becomes unnecessary by trial and error.

  In the embodiment and the modification, when the output current is detected at the measurement timing of five times, the current estimation unit 42 is requested to estimate the output current. However, the measurement timing and the detected output current are stored, and all The output power of each monochromatic light may be estimated collectively after the measurement with the monochromatic light is completed.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

S solar cell evaluation apparatus PV solar cell 1 evaluation light irradiation unit 3 detection unit 4 calculation control unit 8 storage unit 12 evaluation light source unit 17 irradiance detection unit 41 spectral sensitivity calculation unit 42 current estimation unit

Claims (5)

An irradiation unit that sequentially irradiates a plurality of monochromatic lights having different wavelengths as irradiation light to an evaluation target solar cell that needs irradiation of irradiation light for a predetermined time before evaluation,
A detection unit that detects an output of the solar cell when the plurality of monochromatic lights are sequentially irradiated by the irradiation unit;
A plurality of output values detected by the detection unit from the start of irradiation of the monochromatic light by the irradiation unit, and respective elapsed times from the start of irradiation to a time when the detection unit detects the plurality of output values, respectively. using a function related to, an output value measured by the detector when the continued irradiation of the monochromatic light, estimating the output value when the change amount is within a predetermined range, further An estimation unit that calculates an irradiation duration time that is an elapsed time from the start of irradiation until the estimated output value is obtained for each of the plurality of monochromatic lights using the function ;
The wavelength of the monochromatic light from the start of irradiation of the monochromatic light by the irradiating unit instead of the output value estimated by the estimating unit for each of the plurality of monochromatic lights sequentially irradiated by the irradiating unit. A solar cell evaluation apparatus comprising: a spectral sensitivity calculation unit that calculates a spectral sensitivity using an output detected by the detection unit after the irradiation duration calculated by the estimation unit has elapsed . The spectral sensitivity calculation unit, when the irradiation unit emits monochromatic light having a wavelength different from that of the monochromatic light for which the evaluation unit has calculated the irradiation duration, the monochromatic light for which the evaluation unit has calculated the irradiation duration. Based on the wavelength related to the wavelength of the monochromatic light to be emitted and the irradiation duration of the wavelength, the irradiation duration according to the wavelength of the monochromatic light to be emitted is calculated. from the start of irradiation of light, the solar cell evaluation device according to claim 1, characterized in that calculating the spectral sensitivity using a detected by the detecting unit after the lapse of the calculated irradiation duration output. The spectral sensitivity calculation unit is based on the wavelength before and after the wavelength of the monochromatic light irradiated by the irradiation unit and the irradiation duration of the wavelength among the wavelengths of the monochromatic light for which the evaluation unit has calculated the irradiation duration. The solar cell evaluation apparatus according to claim 2 , wherein the irradiation duration time corresponding to the wavelength of the emitted monochromatic light is calculated by interpolation. The spectral sensitivity calculation unit includes a wavelength belonging to a wavelength range including a wavelength of the monochromatic light irradiated by the irradiation unit, and an irradiation duration of the wavelength among the wavelengths of the monochromatic light whose evaluation duration is calculated by the evaluation unit. The solar cell evaluation of Claim 2 which calculates | requires the relational expression of a wavelength and irradiation duration based on this, and calculates the irradiation duration according to the wavelength of the monochromatic light irradiated by the said relational expression apparatus. An irradiation step of sequentially irradiating a plurality of monochromatic lights having different wavelengths as irradiation light to a solar cell to be evaluated that requires irradiation of irradiation light for a predetermined time before evaluation,
The detecting step of detecting the output of the solar cell when the plurality of monochromatic lights are sequentially irradiated by the irradiation step;
A plurality of output values detected in the detection step from the start of irradiation of the monochromatic light in the irradiation step, and respective elapsed times from the start of irradiation to a time when the plurality of output values are detected in the detection step, using a function related to, an output value measured by the detecting step when the continued irradiation of the monochromatic light, estimating the output value when the change amount is within a predetermined range, further An estimation step of calculating an irradiation duration time that is an elapsed time from the start of irradiation until the estimated output value is obtained for each of the plurality of monochromatic lights using the function ;
About the wavelength of the monochromatic light from the start of the monochromatic light irradiation in the irradiation step, instead of the output value estimated in the estimation step, for each of the plurality of monochromatic lights irradiated in sequence by the irradiation step. A solar cell evaluation method comprising: a spectral sensitivity calculation step of calculating a spectral sensitivity using an output detected in the detection step after elapse of the irradiation duration calculated in the estimation step .

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