JP2002111029A - Measurement method and device of photoelectric conversion characteristic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the light reception area of a solar battery to be measured is limited to the minimum area at a laboratory level, and hence a cell, a module, or an array having an area exceeding 400 cm2 cannot be measured in the multi-source method that is suited for the measurement of the photoelectric conversion characteristics of a lamination-type solar battery. SOLUTION: The radiation illuminance of light to be applied is measured or adjusted (S1), the current/voltage characteristics of a reference cell are measured (S2), and the current/voltage characteristics of a sample cell are measured (S3). Then, by comparing the current/voltage characteristics in the reference state of the reference cell with the measurement result of the current/voltage characteristics of the reference cell, deviation from the reference state of the measurement result based on the deviation of illumination light from the reference state is obtained (S4). Based on the deviation of the obtained measurement result, the measurement result of the current/voltage characteristics of the sample cell is corrected (S5), and the photoelectric conversion characteristics of the sample cell are obtained (S6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring photoelectric conversion characteristics, for example, a photoelectric conversion device such as a solar cell, a photodiode, an optical sensor, and an electrophotographic photoreceptor, and in particular, a stacked photoelectric conversion device. It relates to measurement of photoelectric conversion characteristics.

[0002]

2. Description of the Related Art A stacked-type photoelectric conversion device in which a plurality of photoelectric conversion elements having different spectral sensitivities are stacked, a lower wavelength light which cannot be absorbed by an upper photoelectric conversion element corresponding to a light incident side is converted to a lower side. And the sensitivity can be increased. Therefore, such a stacked photoelectric conversion device has been actively developed.

Incidentally, it is very important to accurately measure the output characteristics of a stacked photoelectric conversion device for the following reasons.

[0004] For example, in an inspection at the time of manufacturing and shipping a laminated photoelectric conversion device in which the maximum output is important, a photoelectric conversion device whose maximum output does not reach the rated value is regarded as defective. However, unless accurate output measurement is possible, the maximum output of the photoelectric conversion device to be shipped cannot be guaranteed. In addition, if the measurement error of the output is large and the measurement error changes depending on the state of the measurement device, even if a photoelectric conversion device of the same quality is manufactured, the production yield is not stable due to a change in the inspection threshold. . Furthermore, if the measurement error is added to the inspection threshold in order to guarantee the quality of the photoelectric conversion device to be shipped, it is inevitable that the production yield will be reduced.

If the output of the stacked photoelectric conversion device cannot be accurately predicted, when constructing a system using the stacked photoelectric conversion device, expected system characteristics cannot be obtained or the efficiency of the system cannot be improved. May decrease. When the stacked photoelectric conversion device is a solar cell, it has a great effect on the guarantee of the maximum output of the solar cell, the production yield, the power generation prediction of the power generation system, and the system efficiency.

[0006] However, it is very difficult to accurately measure the output characteristics of the stacked photoelectric conversion device. The most significant is that the output characteristics of the stacked photoelectric conversion device greatly change depending on the spectrum of light to be applied. For example, a case of a double type solar cell (hereinafter abbreviated as “double cell”) in which two semiconductor junctions are stacked and connected in series will be specifically described. When the upper semiconductor junction corresponding to the light incident side is a top cell and the lower semiconductor junction is a bottom cell, the short-circuit current of each cell changes according to the spectrum of light to be irradiated because the cells have different spectral sensitivities. As a result, the short circuit current of the entire double cell,
The fill factor and the open circuit voltage change, and the output characteristics of the double cell change significantly.

On the other hand, a single-layer solar cell comprising a single semiconductor junction (hereinafter abbreviated as "single cell")
In the case of, the short-circuit current changes according to the spectrum of the irradiated light, and has almost no effect on the fill factor and open-circuit voltage.Therefore, if the spectral dependence of the short-circuit current is corrected, almost accurate output characteristics can be measured. can do.

In general, in order to accurately measure the output characteristics of a photoelectric conversion device, it is necessary to specify test conditions such as the intensity and spectrum of light to be irradiated and the temperature of the photoelectric conversion device. For example, in the case of a solar cell, such test conditions are defined as a standard condition (Standard Test Condition) as follows. Solar cell temperature: 25 ° C Irradiation light spectrum: Reference sunlight (Specification of reference sunlight is specified in JIS C 8911) Irradiance of irradiation light: 1000W / m ²

[0009] However, it is very difficult to obtain the spectrum of the reference sunlight in the above-mentioned reference state even if sunlight is used outdoors. This is because the weather conditions under which the reference sunlight can be obtained are very limited. Moreover, when a simulated sunlight source is used indoors, it is impossible to obtain the spectrum of the reference sunlight.

Therefore, in the case of a single cell, the simulated sunlight light source (solar simulator) is not uniform with respect to the position of the spectrum and the irradiance (hereinafter, referred to as "place irregularity").
And according to the time variation rate, they are classified into A, B, and C in order from the state close to the reference sunlight. The classification is J
It is described in IS C 8912 and JIS C 8933. Then, by setting the irradiance of the solar simulator using a solar simulator of class A or B and a secondary reference solar cell having a spectral sensitivity characteristic close to that of the measured solar cell, an error due to a shift in spectrum is corrected. This measuring method is described in JIS C 8913 and JIS C 8934.

The above measurement method is possible because the spectrum is a single cell in which the spectrum substantially affects only the short-circuit current. However, in the case of a stacked solar cell, as described above, the spectrum affects not only the short-circuit current but also the fill factor and the open-circuit voltage, so that the output characteristics cannot be accurately measured by the above-described measurement method. Therefore, as described above
JIS also excludes stacked solar cells.

The following technology has been proposed as a method for accurately measuring the output characteristics of a stacked solar cell.

[0013] By making the spectrum of the solar simulator adjustable when measuring the stacked solar cell and adjusting the spectrum, the stacked solar cell can generate a short-circuit current and a short-circuit current that will be generated under reference sunlight. This is a technique (hereinafter referred to as “multi-source method”) that obtains the value of the fill factor and accurately measures the output characteristics (T. Glatfelterand
J. Burdick, 19th IEEE Photovoltaic Specialists Co
nference, 1987, p. 1187-1193).

That is, each of the plurality of semiconductor junctions constituting the stacked solar cell is a component cell, and each component cell generates a short-circuit current generated under standard sunlight inside the stacked solar cell. Assuming that ref (n is the number of each component cell) and the short-circuit current generated under the solar simulator is In.test, the spectrum of the solar simulator is adjusted for each component cell so as to satisfy the following equation. This means that the short-circuit current and the fill factor of the stacked solar cell match the values under the reference sunlight. In.test = In.ref… (1)

The premise of the above measurement technique is that
That is, a solar simulator capable of adjusting the spectrum is used. In the above-mentioned document, in order to adjust the short-circuit current of each component cell, light from three light sources including a xenon (Xe) lamp and two halogen lamps is separated into three wavelength bands by a filter and then combined. Then, by adjusting the irradiances of the three light sources, the light intensities of the three wavelength bands are controlled, and the spectrum of the light to be synthesized is adjusted.

[0016]

However, the above-mentioned spectrum variable solar simulator can be used with a small area of 400 cm ² or less, but it is difficult to produce a solar simulator having an area exceeding 400 cm ² as follows. Very difficult for reasons. (i) Since a plurality of lights having different spectra are combined, unevenness of the combined light spectrum and irradiance is increased. This unevenness becomes more serious as the irradiation area increases. (ii) Since part of the spectrum of the light from the light source is used, the light intensity tends to be insufficient, and if the irradiation area is large, it is difficult to obtain the irradiance of 1000 W / m ^{2 in} the reference state. (iii) Compared to a normal single light source solar simulator,
The structure becomes complicated, and the manufacturing cost increases significantly. (iv) Adjustment of a spectrum variable solar simulator is complicated, and control requires skill.

Although the multi-source method can accurately measure the output characteristics of a stacked solar cell, the light receiving area of the solar cell to be measured is limited to a laboratory-level minimum area for the above-described reason. It is difficult to measure cells, modules or arrays having an area greater than 400 cm ² . Even if a multi-source measuring device could be manufactured, the cost would be very high. Further, the multi-source method cannot be applied to measurement using sunlight outdoors.

The present invention is intended to solve the above-mentioned problems individually or collectively, and is not affected by the light receiving area and form of a measured object, a measuring place, a measuring light, and the like.
An object is to accurately measure photoelectric conversion characteristics.

[0019]

The present invention has the following configuration as one means for achieving the above object.

The measuring method according to the present invention is a measuring method for measuring a photoelectric conversion characteristic of the object by changing a voltage applied to the object and measuring a current-voltage characteristic of the object. In the reference state, the current-voltage characteristics of the reference object having a configuration substantially equivalent to the measurement object are obtained, and under light irradiation, the current-voltage characteristics of the measurement object and the reference object are measured. A photoelectric conversion characteristic of the measured object is calculated based on a measurement result of the current-voltage characteristic and a current-voltage characteristic of the reference object in the reference state.

[0021] The measuring device according to the present invention, under light irradiation,
A measurement method for measuring a photoelectric conversion characteristic of the measurement object by measuring a current-voltage characteristic of the measurement object, wherein a voltage variable unit that changes a voltage applied to the object and a voltage and a current of the object are detected. Detecting means, the measurement result of the voltage-current characteristics of the measurement object, the measurement result of the current-voltage characteristics of the reference object having a configuration substantially the same as the measurement object, and, in the reference state, the measurement of the reference object measured in advance. It has a calculating means for calculating a photoelectric conversion characteristic of the measured object based on a current-voltage characteristic.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a measuring system according to an embodiment of the present invention will be described in detail with reference to the drawings, using a solar cell as an example.

[Reference Photoelectric Conversion Device] The reference photoelectric conversion device of the stacked type is the most important element in the present embodiment.
Taking a solar cell as an example, it will be referred to as a stacked reference solar cell, but is abbreviated here as “reference cell” or “reference object”. Similarly, a stacked photoelectric conversion device to be measured is abbreviated as “sample cell” or “measurement object”. Less than,
Items required for the reference cell will be described.

(A) The reference cell has the same configuration as the sample cell. That is, the reference cell is desirably made of the same material as the sample cell, and at least the semiconductor portion that performs photoelectric conversion needs to be similarly made of the same material. As a result, the spectral sensitivity of the component cells of the reference cell and the sample cell becomes similar, and the correction of the output characteristics of the sample cell becomes accurate. However, the thicknesses of the semiconductor layers need not be the same.

(B) The component cell for limiting the short-circuit current of the reference cell (hereinafter abbreviated as “rate-limiting cell”) is preferably the same as the rate-limiting cell of the sample cell. Which component cell the rate-limiting cell becomes depends on the spectrum of the light to be irradiated, but it is desirable that the rate-limiting cell of the reference cell and the sample cell be the same at least in the aforementioned reference state. By using the same rate-limiting cell, the short-circuit current of the sample cell can be accurately corrected.

(C) The area of the power generation section of the reference cell is preferably ± 20% or less, more preferably ± 10% or less, of the minimum unit area formed on one substrate constituting the sample cell. In the following, it is desirable that the values are optimally approximated within a range of ± 5% or less. This is because the approximation of the power generation unit areas of the reference cell and the sample cell greatly reduces errors due to uneven spots of irradiated light. When the sample cell is a form in which a plurality of stacked photoelectric conversion devices are connected in series and / or in parallel, that is, a so-called module or array, a minimum unit portion (hereinafter, referred to as a unit) on a single substrate connected in series and / or in parallel The area of the power generation unit (abbreviated as “sub-module”) may be similar to the area of the power generation unit of the reference cell.

(D) It is desirable that the characteristics of the reference cell are processed so as to be stable over time. By stabilizing the characteristics of the reference cell against light, heat and humidity,
The reliability of the current-voltage characteristic in the reference state of the reference cell is improved, and the correction of the output characteristic of the sample cell becomes accurate. Further, the time interval for re-measuring the current-voltage characteristics in the reference state can be widened.

(E) The current-voltage characteristics of the reference cell in the reference state are measured in advance. As a method of measuring the current-voltage characteristic in the reference state, a multi-source method may be used, or another known measurement method may be used. In addition, when the area of the reference cell is large, it is difficult to perform measurement by the multi-source method. Therefore, it is desirable to meet the conditions of reference sunlight outdoors or to perform measurement on a day equivalent thereto (reference sunlight method). . In addition, any method other than the reference sunlight method may be used as long as it is considered that current-voltage characteristics substantially equal to the current-voltage characteristics under the reference sunlight can be reproduced.

(F) It is desirable to use a reference cell whose temperature coefficient of current-voltage characteristics is known. Specifically, it is desirable that the temperature coefficients of the open-circuit voltage, the short-circuit current, and the fill factor be known. When it is difficult to measure the temperature coefficient of the reference cell itself, a temperature coefficient value of an equivalent stacked photoelectric conversion device may be used. When measuring a sample cell using a reference cell, it is desirable to adjust the temperature of the reference cell to 25 ° C.
If it is difficult to adjust the temperature, the temperature is corrected by the temperature coefficient, and the characteristic at 25 ° C. is obtained.

(G) The short-circuit current Jref.n generated when the n-th component cell constituting the reference cell is in the reference state inside the reference cell is the same as that when the n-th component cell of the sample cell is in the reference state inside the sample cell. The generated short-circuit current Jsam.n is preferably in the range of ± 20%, more preferably ± 10%, that is, it is desirable to satisfy the following expression (2) or expression (3).
Here, Jref.n or Jsam.n cannot be measured directly. However, assuming that the spectral sensitivity of each component cell is Qr.n (λ) and Qs.n (λ), the product of the spectral sensitivity and the spectrum Eo (λ) of the reference sunlight is the spectral sensitivity of the cell. Jref.n and Jsam.n can be obtained by integrating over a certain wavelength, that is, the following equation (4)
And Jref.n and Jsam.n can be obtained by equation (5). The measurement of the spectral sensitivity is performed by a known method. When the area of the reference cell or the sample cell is large and it is difficult to measure the spectral sensitivity, it may be estimated from the measurement result of the spectral sensitivity of a small area cell which is considered to have substantially the same spectral sensitivity. 0.8 × Jsam.n ≦ Jref.n ≦ 1.2 × Jsam.n ... (2) 0.9 × Jsam.n ≦ Jref.n ≦ 1.1 × Jsam.n ... (3) Jref.n = ∫Eo (λ) Qr.n (λ) dλ… (4) Jsam.n = ∫Eo (λ) Qs.n (λ) dλ… (5) where Jref.n: short-circuit current of the nth component cell of the reference cell Jsam.n: sample Short circuit current of the nth component cell of the cell Qr.n (λ): Spectral sensitivity of the nth component cell of the reference cell Qs.n (λ): Spectral sensitivity of the nth component cell of the sample cell Eo (λ) : Spectrum of reference sunlight

(H) It is desirable that the so-called mismatch coefficient Mn calculated by the equation (6) showing the relationship between the reference cell and the sample cell be 0.98 or more and 1.02 or less, where Et (λ) is the spectrum of the irradiated light. . Mn = ∫Eo (λ) Qr.n (λ) dλ / ∫Et (λ) Qr.n (λ) dλ × ∫Et (λ) Qs.n (λ) dλ / ∫Eo (λ) Qs.n ( λ) dλ… (6) where Et (λ) is the spectrum of light emitted during measurement

[Correction Method] Next, a method of correcting the result of measuring the output characteristics of the stacked solar cell will be described.

When the irradiance cannot be adjusted (a) The current-voltage characteristics IVsam.t of the sample cell obtained under light irradiation during measurement and the current-voltage characteristics IVr of the reference cell
The data of ef.t is corrected to data of irradiance 1000 W / m ² and temperature 25 ° C. A known method may be used for this correction. IVsam.Data with irradiance and temperature correction
t * and IVref.t *. However, the irradiance is 1000 ± 10
When W / m ² and the cell temperature are in the range of 25 ± 2 ° C., the correction need not be performed. In that case, the following equation holds. IVsam.t * = IVsam.t IVref.t * = IVref.t

(B) From the above-mentioned IVsam.t * and IVref.t *, the characteristic parameters after the following irradiance and temperature corrections of the reference cell and the sample cell, respectively, are obtained by a known method (FIG. 2 and FIG. 2). See Figure 3). Pm.r *: Maximum output of reference cell Pm.s *: Maximum output of sample cell Voc.r *: Open voltage of reference cell Voc.s *: Open voltage of sample cell Isc.r *: Short circuit current of reference cell Isc.s *: Short circuit current of sample cell FF.r *: Fill factor of reference cell FF.s *: Fill factor of sample cell

However, the fill factor FF is generally obtained from the following equation. FF = Pm / (Voc × Isc)

(C) The characteristic parameters of the reference cell in the reference state obtained from the previously measured current-voltage characteristics IVref.o in the reference state of the reference cell are as follows. Pm.ro: Maximum output of the reference cell in the reference state Voc.ro: Open circuit voltage of the reference cell in the reference state Isc.ro: Short circuit current in the reference state of the reference cell FF.ro: Fill factor in the reference state of the reference cell

(D) Since the spectrum of the irradiated light deviates from the reference sunlight, the aforementioned IVref.t * and IVref.o
Is shifted as shown in FIG. Therefore, the maximum output Pm.s * of the sample cell was corrected by equation (7) or (8).
Calculate Pm.so. Pm.so = Pm.s * × Isc.ro / Isc.r * × FF.ro / FF.r *… (7) Pm.so = Pm.s * × Isc.ro / Isc.r * × Pm. ro / Pm.r *… (8)

Equation (7) corrects the spectral dependence of the cell fill factor FF and the short-circuit current Isc, but does not correct the spectral dependence of the open circuit voltage Voc. Equation (8) also corrects the spectral dependence of the open circuit voltage Voc.

The characteristic having a spectral dependency other than the short-circuit current Isc is mainly the fill factor FF, and the spectral dependency of the open-circuit voltage Voc is small. In addition, since the temperature coefficient of the open circuit voltage Voc is generally larger than those of the short-circuit current and the fill factor, the open circuit voltage Voc is easily affected by a temperature measurement error or a temperature correction coefficient error, and is also affected by irradiance. . In other words, when correcting the open-circuit voltage Voc, it is necessary to separate the influence due to the spectrum. However, when the separation is difficult, it may be better not to correct it.

Therefore, when it is difficult to adjust the temperature of the cell to 25 ° C. or when it is difficult to adjust the irradiance to 1000 W / m ² , an error occurs between the irradiance correction and the temperature correction. If it can be considered, the effect of the spectrum of the open-circuit voltage Voc is inseparable, so that the application of equation (7) is preferable.

Conversely, if the error between the irradiance correction and the temperature correction can be considered to be small, such as when the cell temperature is adjusted to 25 ° C. and the irradiance can be adjusted to 1000 W / m ² , open the cell. Since the influence of the spectrum of the voltage Voc can be separated, the application of the equation (8) is preferable.

When the measurement according to the present embodiment is performed outdoors, the time between the time when the irradiance of light is measured, the time when the current-voltage characteristic of the reference cell is obtained, and the time when the current-voltage characteristic of the sample cell is obtained. The deviation is preferably 10 seconds or less, more preferably 5 seconds or less, and most preferably 2 seconds or less. Outdoors, the irradiance and spectrum of sunlight change from moment to moment, so measurements to be compared with each other can be made at the same timing as much as possible, and can be measured under almost equal sunlight conditions, and the measurement accuracy is high. Better.

When the irradiance can be adjusted (e) As in the above-mentioned item (a), the current-voltage characteristics of the reference cell are measured, and the irradiance and the temperature are corrected.

(F) If Isc.r * ≧ Isc.ro, the irradiance of the light source is reduced. Conversely, if Isc.r * <Isc.ro, the irradiance of the light source is increased.

(G) Preferably ± 1%, more preferably ± 1%
Until Isc.r * and Isc.ro match with 0.5% accuracy,
Repeat steps (e) and (f). If the above conditions are met
Isc.r * = Isc.ro

(H) As in the above-mentioned item (a), the current-voltage characteristics of the sample cell are measured, and the irradiance and the temperature are corrected.

(I) The maximum output of the sample cell is corrected by equation (9). Further, the maximum output of the sample cell may be corrected according to Expression (10). Pm.so = Pm.s * × FF.ro / FF.r *… (9) Pm.so = Pm.s * × Pm.ro / Pm.r *… (10)

This is the same as the application of the equations (7) and (8) described above, except that the irradiance is adjusted to 1000 W / m ² , so that an error is included in the temperature correction and the open-circuit voltage Voc spectrum If the influence cannot be separated, use of equation (9) is preferable. If the influence of the spectrum of the open-circuit voltage Voc is small and the error of the temperature correction is small, use of equation (10) is preferable.

(J) If the irradiance of the light source is stable over time, the above-mentioned items (e) to (g) can be omitted to continuously measure different sample cells. According to the temporal stability of the light source, the irradiance of the light source may be adjusted by inserting steps corresponding to the above items (e) to (g) at every certain elapsed time.
Further, when the spectral characteristics of the sample cell change, the rate-limiting cell changes, or when the mismatch coefficient Mn is out of the range of 0.98 to 1.02, the reference cell is changed to an appropriate one from the above viewpoint, and the above (e) It is desirable to redo item (g) from

A simple measuring method when the irradiance can be adjusted (k) As in the above-mentioned item (a), the current-voltage characteristics of the reference cell are measured, and the irradiance and the temperature are corrected.

(L) If pm.r * ≧ Pm.ro, reduce the irradiance of the light source. Conversely, if Pm.r * <Pm.ro, the irradiance of the light source is increased.

(M) preferably ± 1%, more preferably ± 1%
Until Pm.r * and Pm.ro match with 0.5% accuracy,
Repeat (k) and (l). At this time, it may be regarded as Expression (11). Pm.r * = Pm.ro… (11)

(N) As in the above-mentioned item (a), the current-voltage characteristics of the sample cell are measured, and the irradiance and the temperature are corrected. In this case, the maximum output may be Pm.so = Pm.s *. However, the short-circuit current Isc and the fill factor FF are incorrect. This method is suitable when the measurement speed is emphasized and it is desired to measure the maximum output Pm.s as accurately as possible with simple correction.

(O) The measurement of the sample cell can be continuously performed on the same basis as the above-mentioned item (f).

[Sample Cell] The sample cell has a structure in which a plurality of semiconductor junctions are stacked. A device having a structure in which an electrode is taken out from each of the stacked semiconductor junctions is called a four-terminal type when there are two junctions. A device in which a plurality of semiconductor junctions are connected in series and have electrodes at both ends is called a two-terminal type. The measurement method of the present embodiment can be applied to both types of sample cells, but a great effect is obtained when applied to a two-terminal type.

The types of sample cells (stacked photoelectric conversion devices) include a solar cell, a photodiode, an optical sensor, and an electrophotographic photosensitive member.

The types of the semiconductor junction include a pn junction, a pin junction, and an MIS type junction.

As the semiconductor material, crystalline, polycrystalline,
Examples include microcrystalline and amorphous materials.
Group IV or Group IV compounds such as C, SiGe, C, Ge, GaAs,
III-V compounds such as AlGaAs, InP, InSb, ZnSe, ZnO, C
II-VI group compounds such as dS, CdTe, Cu ₂ S, CuInSe ₂ , CuInS ₂
I-III-VI ₂ group compounds such as organic semiconductor, or include mixtures of the aforementioned compounds.

The size and area of the sample cell are not limited in the measuring method of the present embodiment. For example, in the case of a solar cell, devices of various sizes and areas such as cells, sub-modules, modules and arrays can be measured.

It is desirable that the temperature coefficient of the current-voltage characteristic of the sample cell be known. Specifically, open-circuit voltage,
It is desirable to know the temperature coefficient of each of the short-circuit current and the fill factor. When it is difficult to measure the temperature coefficient of the sample cell itself, the value of the equivalent temperature coefficient of the stacked photoelectric conversion device may be used. When measuring the sample cell, it is desirable to adjust the temperature of the sample cell to 25 ° C. When it is difficult to control the temperature, it is necessary to perform temperature correction using the above-mentioned temperature coefficient and obtain the characteristics at 25 ° C.

[Irradiation Light] The light used in the measurement method of this embodiment may be natural light or light from an artificial light source. For example, in the case of a solar cell, sunlight is used or a simulated sunlight light source is preferable.

When using sunlight, the irradiance is preferably from 500 to 1500 W / m ² , more preferably from 800 to 1200 W / m ²
It is desirable to measure within the range. In addition, since the temperature of the reference cell or the sample cell tends to rise, it is preferable that the sunlight is shielded until the measurement is started, and that the sunlight hits the reference cell or the sample cell immediately before the measurement. In this case, the temperature rise of the cell is suppressed, the correction amount based on the above-described temperature coefficient is reduced, the error due to the temperature correction is reduced, and the measurement becomes more accurate.

When a simulated sunlight source is used, a known solar simulator is suitable. As a light source lamp,
Xenon lamps, metal halide lamps and the like are preferably used. The lighting method may be continuous lighting or pulse lighting. When a simulated sunlight light source is used, the spectrum becomes larger or smaller depending on the usage time of the lamp. Since the measurement method of the present embodiment corrects an error due to a spectrum, it is possible to accurately measure the output characteristics of a stacked photoelectric conversion device that is sensitive to a spectrum.

When measuring a cell or module having a large area, the effective irradiation area of the solar simulator must be increased, and a solar simulator excellent in both the degree of matching of the spectrum and the unevenness of the irradiance is required. As described above, as the area increases, the manufacturing cost of the solar simulator increases rapidly. In the case of the measuring method according to the present embodiment, since the place unevenness of the irradiance of the solar simulator is emphasized and the matching degree of the spectrum can be compromised, an accurate measuring system corresponding to a large area can be realized at low cost. Can be.

[Irradiance Detector] The irradiance of light applied to the cell can be determined by using a known solar cell, photodiode, pyranometer using a thermocouple, etc. Irradiance is calibrated. Therefore, the reference cell may be used for the irradiance detector from the beginning.

[Voltage Detector and Current Detector] The voltage and current detectors 101 and 102 shown in FIG. 1 are known in the art such as a digital multimeter or a combination of a resistor and an analog-digital conversion card. Means may be used.

[Power Supply] As the power supply 103 for supplying power to the cell 104 or 105 shown in FIG. 1, a bipolar power supply whose voltage can be varied is used. If the voltage applied to the cell 104 or 105 is variable or can be swept, known means such as an electronic load or discharging of the charge stored in the capacitor can be used in place of the power supply 103.

[Spectrum Measuring Device] When calculating the above-described mismatch coefficient Mn, it is necessary to measure the spectrum of the irradiated light. In that case, a known spectrum radiometer is suitably used.

[Measurement Control and Data Processing Unit] It is desirable to provide a measurement control and data processing unit such as a personal computer as a unit for controlling the above-mentioned measuring instruments and a unit for processing measured data.

[Measurement Procedure] FIG. 19 is a flowchart showing an example of the measurement procedure of the present embodiment.

First, the irradiance of the irradiated light is measured or adjusted by the irradiance detector (S1). Next, the current-voltage characteristics of the reference cell are measured (S2), and the current-voltage characteristics of the sample cell are measured (S3). That is, while varying the voltage applied to the measurement target, the voltage applied to the measurement target and the supplied current are measured to obtain a current-voltage characteristic. Note that steps S2 and S3 are preferably executed almost simultaneously, at least within a short time.

Next, by comparing the current-voltage characteristic of the reference cell in the reference state with the measurement result of the current-voltage characteristic of the reference cell, the measurement result based on the deviation of the irradiation light from the reference state is calculated from the reference state. A shift is obtained (S4). And
Based on the obtained deviation of the measurement result, the measurement result of the current-voltage characteristic of the sample cell is corrected (S5), and the photoelectric conversion characteristic of the sample cell is obtained (S6).

[0073]

[Example 1] A pin junction top cell using amorphous silicon (hereinafter referred to as “a-Si”) for an i-layer, and amorphous silicon germanium (hereinafter referred to as “a-SiGe”) for an i-layer pin junction middle cell and a-Si
The output characteristics of a triple-type solar cell having a three-layer structure of a pin junction bottom cell using Ge as the i-layer were measured by a known pulsed light type solar simulator using a xenon lamp as a light source.

A triple type solar cell is a cell having a size of about 1 cm × 1 cm formed on a single stainless steel substrate.
This is the state of a single unit before being connected in series or parallel. Further, no surface protection layer is formed. The solar simulator has an effective irradiation area of about 10cm x 10cm, the time variation of irradiance is less than ± 1%, and the unevenness of irradiance is less than ± 2%.

A known bipolar power supply was used as the power supply 103, and the voltage was swept by a personal computer. In addition, a known digital multimeter was used for the voltage and current detectors 101 and 102, and measured voltage and current data were obtained by a personal computer. With the above configuration, the current-voltage characteristics of the cell were obtained.

The reference cell has the same structure as the sample cell,
A triple-type solar cell of the same size was irradiated with light for 1000 hours using a solar simulator to cause photodegradation, and was used in which the change over time in characteristics was stabilized. In the reference cell, current-voltage characteristics in a reference state are measured in advance by a multi-source method. By stabilizing the characteristics of the reference cell, even if light is irradiated on the reference cell during measurement, the characteristics of the reference cell do not change, so that the measurement result becomes accurate.
Further, the time interval for re-measuring the current-voltage characteristics in the reference state of the reference cell can be widened.

A reference cell was used as the irradiance detector, and the irradiance of the solar simulator was adjusted to 1000 W / m ² so that the short-circuit current of the reference cell matched the short-circuit current in the reference state. Therefore, in the case of the present embodiment, Isc.r * = Isc.ro can be regarded as described in the above-described correction method.

A copper block and a Peltier element were provided on the back surfaces of the stainless steel substrates of the sample cell and the reference cell, and the temperature of the cell was adjusted to 25 ° C. ± 1 ° C. Therefore, the present embodiment corresponds to “when the irradiance is adjustable” described in the above-described correction method, and the irradiance and the temperature of the cell are adjusted to 1000 W / m ² and 25 ° C. according to the reference state.
Therefore, it is not necessary to correct the illuminance and the temperature of the obtained current-voltage characteristics.

Therefore, the maximum output Pm.s * is obtained from the current-voltage characteristics of the sample cell, and FF.r * is obtained from the current-voltage characteristics of the reference cell. .ro was determined, and the correction was performed by equation (9) to determine the maximum output Pm.so. The result is shown in FIG.

When the spectral sensitivity characteristics of a sample which was prepared simultaneously with the sample cell and considered to have the same characteristics as the sample cell were measured by a known method, a solid line 401 shown in FIG.
From 403. Further, when the spectral sensitivity characteristics of the reference cell were measured, characteristics such as those indicated by broken lines 404 to 406 shown in FIG. 4 were obtained. Since the reference cell is light-degraded until its characteristics are stabilized, the spectral sensitivity and short-circuit current of each component cell are slightly smaller than those of the sample cell.

When the measured spectral sensitivity characteristics and the spectrum of the reference sunlight were integrated by wavelength according to the equations (4) and (5), the results shown in FIG. 6 were obtained. FIG. 6 also summarizes the results of measuring the spectrum of the solar simulator with a known spectrum radiometer and calculating the mismatch coefficient by equation (6).

FIG. 6 shows that the top cell is the component cell that controls the current of the entire triple solar cell in both the sample cell and the reference cell. Also, it can be seen that the ratio of the short-circuit current of each component cell of the sample cell and the reference cell is within ± 10%. further,
The mismatch coefficient of each component cell of the sample cell with respect to the reference cell under light irradiation is 0.99 to 1.00.

As described above, the reference cell has a spectral sensitivity characteristic close to that of the sample cell, and the rate-limiting cell is the same.
Since the mismatch coefficient is close to 1, the accuracy of the correction result of the output characteristics of the sample cell is improved.

[0084]

Comparative Example 1 In order to verify the accuracy of the measurement result of Example 1 described above, the sample cell of Example 1 was measured by a multi-source method.

That is, a solar simulator (multi-source simulator) whose spectrum can be adjusted is:
The spectrum of the solar simulator was adjusted so that the current of each of the top cell, the middle cell, and the bottom cell of the sample cell was equal to the value in the reference state.
The spectrum of the solar simulator at this time was measured by a known spectrum radiometer.

Except for using the multi-source simulator, the same as in Example 1 was used as the reference cell except that the multi-source simulator was used, and the irradiance of the solar simulator was adjusted to 1000 W / m ² by the reference cell. The current-voltage characteristics were measured while the temperature of the reference cell was adjusted to 25 ° C. However, this time, the output characteristics were not corrected by the reference cell. FIG. 7 shows the measurement results.

The results before and after the correction in the first embodiment are divided by the respective values shown in FIG. 7, and the increase or decrease in the values is expressed as a percentage as shown in FIG. From the results shown in FIG. 8, the measurement method according to the present embodiment without using a device such as a multi-source simulator, that is, a measurement method that corrects the result measured using a general solar simulator, It became clear that an accurate measurement result close to the result was obtained.

[0088]

Example 2 The same sample cell as in Example 1 was measured in the same manner as in Example 1, and instead of correcting the measurement result using Expression (9), the result corrected using Expression (10) is shown in FIG. Shown in The results before and after the correction of the second embodiment shown in FIG. 9 are divided by the respective values shown in FIG. 7, and the increase or decrease of the values is displayed as a percentage, as shown in FIG. From the results shown in FIG. 10, it has been clarified that the measurement method of the present embodiment using the equation (10) can also obtain an accurate measurement result close to the measurement result by the multi-source method.

[0089]

Example 3 Top cell of pin junction using a-Si for i layer,
The output characteristics of a double-layer solar cell with a two-layer structure of a pin junction bottom cell using microcrystalline silicon (hereinafter referred to as "μc-Si") as an i-layer are measured by a known solar simulator using a xenon lamp as a light source. did.

The double type solar cell is a submodule having a size of about 25 cm × 18 cm formed on one stainless steel substrate, and is a single unit before being connected in series or parallel. Further, no surface protection layer is formed. The solar simulator has an effective irradiation area of about 130cm x 80cm, the irradiance unevenness is less than ± 3%, and the irradiance unevenness within the submodule area is less than ± 1.5%. The cumulative lighting time of the xenon lamp at the time of measurement was 400 hours.

A known electronic load was used for the power supply 103, and the voltage was swept by a personal computer. Also,
A combination of a resistor and an analog-digital conversion card was used for the voltage and current detectors 101 and 102, and measured voltage and current data were acquired by a personal computer. With the above configuration, the current-voltage characteristics of the submodule were obtained.

The reference sub-module is a double-type solar cell sub-module having the same structure and the same size as the sample sub-module. Was used. In addition, the voltage-current characteristics of the reference sub-module are measured in advance outdoors under sunlight conditions that meet or meet the reference sunlight conditions, irradiance and temperature are corrected, and the current in the reference state is corrected. Voltage characteristics are obtained.

By matching the area of the reference sub-module with that of the sample sub-module, it was possible to greatly reduce errors due to unevenness in the irradiance of the solar simulator.

A reference sub-module was used as the irradiance detector, and the irradiance of the solar simulator was adjusted to 1000 W / m ² so that the short-circuit current of the reference sub-module matched the short-circuit current in the reference state. Therefore, in the case of this embodiment, Isc.r * = Isc.ro, as described in the above-described correction method.
Can be considered

The temperature of the sample submodule was 27 ° C., and the temperature of the reference submodule was 27.5 ° C. The current-voltage characteristics of both submodules were corrected by a temperature correction coefficient obtained in advance using a double-type solar cell having the same structure.

After the temperature correction, the maximum output Pm.s * is obtained from the current-voltage characteristics of the sample submodule, and the FF.r * is obtained from the current-voltage characteristics of the reference submodule. FF.ro is determined from the current-voltage characteristics of
asked for so. The result is shown in FIG.

The current-voltage characteristics of the sample submodule are measured outdoors under sunlight conditions that meet or conform to the reference sunlight conditions, and the irradiance and temperature are corrected to obtain the current-voltage characteristics in the reference state. Acquired properties. Pm, Voc, Isc and
FIG. 12 summarizes the results of comparison between the output characteristics of the FF and the output characteristics at the time of measurement and after correction shown in FIG.

From the results shown in FIG. 12, the result of measurement using a general solar simulator can be corrected by the measuring method of the present embodiment without carefully selecting weather conditions and performing outdoor measurement with reference sunlight. By doing so, it became clear that an accurate measurement result close to the measurement result of the reference solar method was obtained.

[0099]

Example 4 Top cell of pin junction using a-Si for i-layer,
The output characteristics of a double-layer solar cell module having a two-layer structure of a pin junction bottom cell using single-crystal silicon (hereinafter referred to as “c-Si”) as an i-layer were measured outdoors.

A double type solar cell module is about 10 cm ×
Double solar cells created on a 10 cm single crystal silicon wafer are connected in 15 series x 3 parallel, and the size is about 95 cm x 55 cm
Is formed in a so-called super straight type module. Outdoor measurements were performed on sunny days with an incident angle of direct solar radiation within 10 degrees and an irradiance of 800 W / m ² or more. However, since the measurement is performed under more general-purpose weather conditions than limited weather conditions such as the reference sunlight method, the sunlight spectrum does not satisfy the conditions of the reference sunlight.

A known electronic load was used as the power supply 103, and the voltage was swept by the function of the electronic load. In addition, a known digital multimeter was used for the voltage and current detectors 101 and 102, and data of the measured voltage and current were acquired by a notebook computer. With the above configuration, the current-voltage characteristics of the module were obtained.

As a reference module, a double-type solar cell sub-module having the same module structure and a size of about 10 cm × 10 cm was irradiated with light for 1000 hours by a solar simulator to be light-degraded, thereby stabilizing the time-dependent change in characteristics. Was used. The current-voltage characteristics of the reference module in the reference state are measured in advance by the multi-source method.

By matching the area of the reference module with the area of the solar cell of the sample module, errors in temperature correction are reduced, and measurement errors in output characteristics are reduced. The reference module and the sample module are installed on the same platform on the same plane, and the incident angles of direct solar radiation are aligned.
At the same time, the current-voltage characteristics were measured to make the measurement conditions uniform.

A reference module was used as the irradiance detector, and the irradiance was measured by the short-circuit current of the reference module.

The temperature of the sample module is 25 ° C. indoors.
Voltage Voc measured using a pulsed solar simulator in a temperature-controlled state and the open-circuit voltage V measured outdoors
oc was calculated based on the temperature coefficient. The temperature of the reference module was also calculated based on the temperature coefficient from the open-circuit voltage Voc measured by the multi-source method in a state where the temperature was controlled indoors at 25 ° C. and the open-circuit voltage Voc measured outdoors. Thereafter, the temperature and irradiance of the current-voltage characteristics of both modules were corrected using the temperature correction coefficient value and the series resistance value obtained using the double-type solar cell having the same structure.

After the temperature correction and the irradiance correction, the maximum output Pm.s * is obtained from the current-voltage characteristics of the sample module, and the FF.r * is obtained from the current-voltage characteristics of the reference module. FF.ro is obtained from the voltage characteristics, corrected according to equation (7), and the maximum output Pm.
asked for so. Further, in the case of the present embodiment, even when the correction was performed using the equation (8), the value was the same as that obtained when the equation (7) was used. FIG. 13 shows the result.

The current-voltage characteristics of the sample module were measured outdoors under sunlight conditions satisfying or meeting the standard sunlight conditions, the irradiance and temperature were corrected, and the current-voltage characteristics in the reference state were measured. I got Output characteristics of Pm, Voc, Isc and FF obtained from the result and figure
FIG. 14 summarizes the results of comparing the output characteristics at the time of measurement and after correction shown in FIG.

From the results shown in FIG. 14, the measurement method of the present embodiment corrects the results measured by outdoor measurement without carefully selecting the weather conditions and waiting for the day when the reference sunlight conditions are obtained. It was found that an accurate measurement result close to the measurement result of the reference sunlight method could be obtained.

In Japan, the meteorological conditions that meet the standard solar light method can be met only a few times a year in Japan. However, according to the measuring method of the present embodiment, the conditions of clear sky and irradiance of 800 W / m ² or more are met. If it can be obtained, measurement can be performed any number of times a day, and the number of days for outdoor measurement can be greatly increased.

[0110]

Fifth Embodiment The triple solar cell of the first embodiment has a size of about 25
A submodule was formed on a single stainless steel substrate of cm × 35 cm. Using a galvanized steel plate as a support, five sub-modules were connected in series, and a surface protection layer, a bypass diode, a junction box, and the like were added to form a roof material type module of about 140 cm × 42 cm. Five strings of 20 modules connected in series were connected in parallel to form a solar cell array. The output of this solar cell array is 3.2 kW. This solar cell array is
It also functions as a roof material, is installed as a roof of a building, and is connected to a power conditioner such as an inverter via a junction box, and functions as a part of a solar power generation system.

The output characteristics of the solar cell array were measured with sunlight while being installed on the roof. The measurement is
When the weather was fine, the time when the incident angle of direct solar radiation was within 10 degrees was selected, and the irradiance was 800 W / m ² or more. However,
Since the measurement is performed in more general weather conditions than in limited weather conditions such as the reference sunlight method, the sunlight spectrum does not satisfy the conditions of the reference sunlight.

After the connection between the solar cell array and the power conditioner was cut off in the connection box, the output of the solar cell array was connected to the power supply 103. A known method of discharging the charge accumulated in the capacitor was used for the power supply 103, and the voltage was swept by discharging the capacitor. In addition, a known digital multimeter was used for the voltage and current detectors 101 and 102, and data of the measured voltage and current were acquired by a notebook computer. With the above configuration, the current-voltage characteristics of the solar cell array were obtained.

As a reference module, a triple solar cell sub-module having the same module structure as the sample and having a size of about 25 cm × 35 cm was deteriorated by injecting a current for 1500 hours by a known forward bias current injection method. The thing which stabilized the time-dependent change of was used. The current-voltage characteristics of the reference module in the reference state are measured in advance by the reference sunlight method.

By matching the area of the reference module with the area of the sub-module of the solar cell array as a sample, errors in temperature correction are reduced, and measurement errors in output characteristics are reduced. The reference module and the solar cell array as a sample were installed at the same angle with respect to sunlight, the incident angles of direct solar radiation were adjusted, and at the same time, current-voltage characteristics were measured to adjust the measurement conditions.

The irradiance detector was a reference module, and the irradiance was measured by the short-circuit current of the reference module.

The temperature of the solar cell array was determined by weighted averaging the temperatures measured at a plurality of points by a radiation thermometer from the surface side of the array at an expected angle such that no shadow was formed on the array. The temperature of the reference module was measured using a copper-constantan sheet-type thermocouple and a digital thermometer, which were attached almost at the center of the back surface of the module. Thereafter, the temperature and irradiance of the current-voltage characteristics of both modules were corrected using the temperature correction coefficient value and the series resistance value obtained using the triple-type solar cell having the same structure. Further, the degree of contamination of the solar cell array was estimated, and the current-voltage characteristics were corrected using the contamination correction coefficient.

From the current-voltage characteristics of the solar cell array after temperature correction, irradiance correction and dirt correction, the maximum output Pm.s *,
FF.r * is obtained from the current-voltage characteristics of the reference module after temperature correction and irradiance correction, and FF.ro is obtained from the current-voltage characteristics of the reference module in the previously measured reference state.
The maximum output Pm.so was obtained by performing correction according to the equation (7). The result is shown in FIG.

It has been difficult to measure the current-voltage characteristics of the solar cell array outdoors under weather conditions where the sunlight satisfies the reference sunlight. Therefore, when a solar cell module constituting a solar cell array was manufactured, the current-voltage characteristics were measured one by one using a pulsed light type solar simulator, and the output characteristics were obtained in the same manner as in the method of Example 4. . The output characteristics of each module are combined in 20 columns and 5 parallel,
The output characteristics of the solar cell array were determined. Finally, the light degradation rate after the solar cell array was installed and the loss due to the connection cable and the backflow prevention diode were corrected to obtain the corrected output characteristics after the solar cell array was constructed. This output characteristic and figure
FIG. 16 summarizes the results of comparing the output characteristics at the time of measurement and after correction shown in FIG.

From the results shown in FIG. 16, by using the measuring method of the present embodiment, it is possible to correct the measurement result of the outdoor measurement without carefully selecting the weather conditions and waiting for the day when the reference sunlight condition is obtained. It was clarified that an accurate measurement result close to the result obtained by combining the results measured using the solar light method was obtained.

[0120]

Example 6 The output characteristics of a stacked optical sensor having a pn junction top cell made of AlGaAs and a pn junction bottom cell made of GaAs were measured by a known solar simulator using a metal halide lamp as a light source.

The optical sensor is formed on one GaAs wafer and then cut into a size of about 1 cm × 1 cm, and is in a state before being unitized as a sensor. The solar simulator has an effective irradiation area of about 10cm × 10cm, the time variation of irradiance is less than ± 1%, and the unevenness of irradiance is less than ± 2%.

A known electronic load was used as the power supply 103, and the voltage was swept by a personal computer. A known combination of a resistor and an analog-to-digital conversion card was used for the voltage and current detectors 101 and 102, and measured voltage and current data were acquired by a personal computer. With the above configuration, the current-voltage characteristics of the optical sensor were obtained.

As a reference cell, a cell having an average output characteristic and a spectral sensitivity characteristic was selected and used from 100 laminated optical sensors having the same structure and the same size. The current-voltage characteristics of the reference cell in the reference state are measured in advance by the multi-source method.

By matching the area of the reference cell with the area of the sample, it was possible to greatly reduce errors due to unevenness in the irradiance of the solar simulator.

A reference cell is used for the irradiance detector, and the solar simulator is controlled so that the maximum output of the reference cell coincides with the maximum output in the reference state, that is, so as to satisfy Equation (11) of the correction method described above. irradiance was adjusted to 1000W / m ^2.

The temperatures of the sample and the reference cell were adjusted to 25 ° C. ± 1 ° C. by providing a copper block and a Peltier element on the back surface of the stainless steel substrate.

Therefore, in this embodiment, when the irradiance is adjustable, the irradiance and the temperatures of the cell and the sample are adjusted to 1000 W / m ² and 25 ° C.
Therefore, it is not necessary to correct the illuminance and the temperature of the obtained current-voltage characteristics.

The results of calculating the output characteristics from the current-voltage characteristics of the optical sensor obtained by the above measurement are shown in the column of output calibration measurement in FIG.

For comparison with the measurement method of the present embodiment, the irradiance of the solar simulator is adjusted so that the short-circuit current of the reference cell does not match the maximum output so as to satisfy the equation (11). The results of the measurement performed in exactly the same manner as in the above-described example except that the adjustment was made are shown in the column of the current calibration measurement in FIG.

The current-voltage characteristics of the optical sensor in the reference state were measured by a multi-source method. FIG. 18 summarizes the results of comparing the output characteristics of Pm, Voc, Isc, and FF obtained from the results with the output characteristics at the time of the output calibration measurement and the current calibration measurement shown in FIG.

From the results shown in FIG. 18, the measurement method according to the present embodiment that matches the maximum output of the reference cell using equation (11) of the above-described correction method does not perform measurement by the multi-source method, and It was found that even with a solar simulator, an accurate maximum output measurement result close to the measurement result of the multi-source method could be obtained.

In the output calibration measurement of the present embodiment, since the measurement of the maximum output is emphasized, there are errors in the short-circuit current and the fill factor. improves.

In the output calibration measurement of this embodiment, since the measurement process is simple, the time required for the measurement is reduced, and a large number of samples can be measured in a short time.
Therefore, it is suitable for an inspection system of a production line that needs to automatically measure a large number of samples.

As described above, according to the measuring method of the present embodiment, the measurement of the output characteristics of the stacked photoelectric conversion device becomes accurate. In addition, the same measurement accuracy can be obtained without using an expensive measuring device such as a multi-source method, so that the cost can be reduced. Also, unlike the multi-source method or the standard solar light method, complicated control is not required, and strict selection of measurement conditions is not required, equivalent measurement accuracy can be obtained, and the measurement method can be simplified.

Further, among the individual semiconductor junctions constituting the stacked photoelectric conversion device, the semiconductor junction which limits the short-circuit current of the stacked photoelectric conversion device under light irradiation is defined as a rate-limiting cell. Between the target stacked-type photoelectric conversion device and the reference stacked-type photoelectric conversion device, since the rate-limiting cell is the same semiconductor junction, the degree of approximation of spectral sensitivity is improved,
The errors in the short-circuit current and the fill factor are reduced, and the measurement accuracy of the output characteristics of the stacked photoelectric conversion device is improved.

[0136]

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine) Machine, facsimile machine, etc.).

Further, an object of the present invention is to provide a storage medium (or a recording medium) on which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and to provide a computer (a computer) of the system or the apparatus. Alternatively, it is needless to say that the present invention can also be achieved by a CPU or an MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. Also,
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also the operating system (OS) running on the computer based on the instructions of the program code.
It goes without saying that a case where the functions of the above-described embodiments are implemented by performing some or all of the actual processing, and the processing performs the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. Needless to say, the CPU included in the function expansion card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts described above.

[0140]

As described above, according to the present invention,
The photoelectric conversion characteristics can be accurately measured at low cost without being affected by the light receiving area and form of the measurement object, the measurement location, the measurement light, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a measurement device according to an embodiment;

FIG. 2 shows current-voltage characteristics (IVr) of a reference cell under light irradiation.
ef.t *) and current-voltage characteristics in the reference state (IVref.o)
A diagram showing an example of

FIG. 3 shows current-voltage characteristics of a sample cell under light irradiation.
A diagram showing an example of (IVsam.t *),

FIG. 4 is a diagram showing a spectral sensitivity characteristic of a sample cell (solid line) and a spectral sensitivity characteristic of a reference cell (dashed line) in Example 1.

FIG. 5 is a diagram showing measurement results in Example 1.

FIG. 6 is a diagram showing a calculation result of a short-circuit current generated in a reference state in a component cell in the first embodiment,

FIG. 7 is a diagram showing measurement results in Comparative Example 1.

FIG. 8 is a diagram showing a verification result of Example 1.

FIG. 9 is a diagram showing measurement results in Example 2.

FIG. 10 is a diagram showing a verification result of Example 2.

FIG. 11 is a view showing measurement results in Example 3.

FIG. 12 is a view showing a verification result of Example 3.

FIG. 13 is a diagram showing measurement results in Example 4.

FIG. 14 is a diagram showing a verification result of Example 4.

FIG. 15 is a diagram showing measurement results in Example 5.

FIG. 16 is a diagram showing a verification result of Example 5.

FIG. 17 shows a measurement result in Example 6.

FIG. 18 is a diagram showing a verification result of Example 6.

FIG. 19 is a flowchart illustrating an example of a measurement procedure according to the present embodiment.

Claims (15)

[Claims] 1. A measuring method for measuring a photoelectric conversion characteristic of a measurement object by changing a voltage applied to the measurement object and measuring a current-voltage characteristic of the measurement object, wherein the measurement is performed in a reference state. Obtaining current-voltage characteristics of a reference object having a configuration substantially equivalent to that of the object, measuring the current-voltage characteristics of the measured object and the reference object under light irradiation, and measuring the current-voltage characteristics of the measured object and the reference object. And a photoelectric conversion characteristic of the measured object based on a current-voltage characteristic of the reference object in the reference state. 2. A ratio between a measurement result of the short-circuit current of the reference object and a short-circuit current in the reference state, and a ratio between a measurement result of a fill factor of the reference object and a fill factor in the reference state. 2. The measurement method according to claim 1, wherein a photoelectric conversion characteristic of the measured object is calculated by correcting a measurement result of a voltage-current characteristic of the measured object. 3. A ratio between a measurement result of the short-circuit current of the reference object and a short-circuit current in the reference state, and a ratio between a measurement result of a maximum output of the reference object and a maximum output in the reference state. 2. The measuring method according to claim 1, wherein a photoelectric conversion characteristic of the measured object is calculated by correcting a measurement result of a voltage-current characteristic of the measured object. 4. The irradiance of the simulated sunlight used for light irradiation is adjusted so that the maximum output of the reference object is substantially equal to the maximum output of the reference object in the reference state. 4. The measuring method according to claim 1, wherein: 5. The measurement method according to claim 1, wherein the measurement object is a photoelectric conversion device in which a plurality of semiconductor junctions are stacked. 6. A rate-limiting cell for limiting a short-circuit current of the measured object under light irradiation, and a rate-limiting cell for the reference object, among at least a plurality of stacked semiconductor junctions, are the same semiconductor junction. 6. The measuring method according to claim 5, wherein 7. The measuring method according to claim 1, wherein the reference is a stacked photoelectric conversion device. 8. A measuring method for measuring a current-voltage characteristic of a measured object under light irradiation to measure a photoelectric conversion characteristic of the measured object, comprising: a voltage variable means for changing a voltage applied to the object. Detecting means for detecting the voltage and current of the object, measurement results of voltage-current characteristics of the measurement object, measurement results of current-voltage characteristics of a reference object having a configuration substantially equivalent to the measurement object,
In addition, in a reference state, there is provided a measuring apparatus comprising a calculating means for calculating a photoelectric conversion characteristic of the measurement object based on a current-voltage characteristic of the reference object measured in advance. 9. The method according to claim 1, wherein the calculating unit calculates a ratio between a measurement result of the short-circuit current of the reference object and a short-circuit current in the reference state, and a measurement result of the fill factor of the reference object and the fill factor in the reference state. 9. The measuring apparatus according to claim 8, wherein a photoelectric conversion characteristic of the measured object is calculated by correcting a measurement result of a voltage-current characteristic of the measured object based on the ratio. 10. The calculation means according to claim 1, wherein a ratio of a measurement result of the short-circuit current of the reference object to a short-circuit current in the reference state,
Further, based on a ratio between the measurement result of the maximum output of the reference object and the maximum output in the reference state, the photoelectric conversion characteristic of the measurement object is calculated by correcting the measurement result of the voltage-current characteristic of the measurement object. 9. The measuring device according to claim 8, wherein: 11. The method according to claim 11, further comprising: simulated sunlight used for light irradiation, wherein the irradiance of the simulated sunlight is such that a maximum output of the reference object is substantially equal to a maximum output of the reference object in the reference state. 10. The method according to claim 9, wherein
A measuring device according to any one of claims 1 to 11. 12. The measuring device according to claim 8, wherein the object to be measured is a stacked photoelectric conversion device. 13. The measuring device according to claim 8, wherein the reference object is a stacked photoelectric conversion device. 14. A program for controlling a measuring device to execute the measurement of the photoelectric conversion characteristic according to claim 1. Description: 15. A recording medium on which the program according to claim 14 is recorded.