JP4233330B2 - Photovoltaic device inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a photovoltaic device inspection apparatus and inspection method, and in particular, a photovoltaic device for inspecting a photovoltaic device having a pin junction.InspectionRegarding the inspection method.
[0002]
[Prior art]
  Conventionally, various photovoltaic devices (solar cells) having a pin junction are known (see, for example, Patent Document 1).
[0003]
  Patent Document 1 includes a plurality of unit cells in which a substrate-side thin film electrode, an amorphous semiconductor layer (amorphous semiconductor layer) made of a pin junction, a metal thin film, and a transparent conductive film are stacked in this order on a glass substrate. An integrated photovoltaic device is disclosed.
[0004]
  Conventionally, an integrated photovoltaic device as disclosed in Patent Document 1 above.ofVarious methods for inspecting the film thickness of the power generation layer (i layer) have been proposed.
[0005]
[0006]
  For exampleAs a first example of the conventional method for measuring the film thickness of the power generation layer (i layer), a measurement method using a surface roughness meter is known. In this measurement method using a surface roughness meter, first, a photoresist is formed on a part of a portion where a metal electrode of a photovoltaic device and a pin layer without a transparent conductive film are exposed. Then, using the photoresist as a mask, Freon gas (CF_Four) And oxygen gas (O₂) And dry etching the pin layer using a mixed gas, and then the photoresist is removed. After this, the height of the step between the portion covered with the mask and the portion from which the pin layer was removed by dry etching was measured using a surface roughness meter provided with a needle-like measuring portion at the tip. By measuring, the total film thickness of the pin layer is measured. And the film thickness of i layer is calculated | required by deducting the design film thickness of the film thickness of p layer and n layer from the total film thickness of the measured pin layer.
[0007]
  Further, as a second example of the conventional method for measuring the film thickness of the power generation layer (i layer), a measurement method by cross-sectional SEM (Scanning Electron Microscope) observation is known. In this measurement method by cross-sectional SEM observation, first, a predetermined portion of the photovoltaic device is cut in a direction perpendicular to the surface of the photovoltaic device to expose the section of the photovoltaic device. And the total film thickness of a pin layer is measured by measuring the distance between two interfaces of a pin layer and the other layer formed in the upper and lower sides of a pin layer using SEM. And the film thickness of i layer is calculated | required by deducting the design film thickness of p layer and n layer from the total film thickness of a pin layer.
[0008]
  Further, as a third example of the conventional method for measuring the film thickness of the power generation layer (i layer), a film thickness measurement method based on photosensitivity measurement is known. In this film thickness measurement method based on photosensitivity measurement, first, the photosensitivity of the power generation layer (i layer) with respect to light irradiation is measured using an inspection apparatus including a dark room and a spectroscope. The measured light sensitivity is plotted on the vertical axis, and the wavelength of the irradiated light is plotted on the horizontal axis. In this graph, it is known that the peak of the photosensitivity increases in width toward the longer wavelength side as the film thickness of the power generation layer (i layer) increases. Thereby, the film thickness of a power generation layer (i layer) is calculated | required by comparing this graph with the parameter | index about the correlation of the film thickness of the power generation layer (i layer) and the photosensitivity created beforehand.
[0009]
  Further, as a fourth example of the conventional film thickness measurement method for the power generation layer (i layer), a film thickness measurement method by reflectance spectrum measurement is known. In this film thickness measurement method by reflectance spectrum measurement, an inspection apparatus having a dark room and a spectroscope is used, and the reflectance spectrum of light that is not absorbed by the power generation layer (i layer) with respect to irradiation light is obtained. taking measurement. The intensity of the measured reflectance spectrum is plotted on the vertical axis, and the wavelength of irradiation light is plotted on the horizontal axis. In this graph, it is known that the rising angle of the reflectance spectrum in the vertical axis direction becomes smaller as the film thickness of the power generation layer (i layer) increases. Thereby, the film thickness of the power generation layer (i layer) is obtained by comparing this graph with the index about the correlation between the film thickness of the power generation layer (i layer) and the reflectance spectrum prepared in advance. .
[0010]
[Patent Document 1]
          JP-A-5-251723
[0011]
[Problems to be solved by the invention]
[0012]
  UpThe measurement method using the surface roughness meter described above has a problem that it is difficult to non-destructively inspect the photovoltaic device because dry etching is performed. In addition, the above-described measurement method by cross-sectional SEM observation also has a problem that it is difficult to non-destructively inspect the photovoltaic device because the photovoltaic device is cut.
[0013]
  In addition, the above-described film thickness measuring method of the power generation layer (i layer) by photosensitivity measurement and the film thickness measurement method of the power generation layer (i layer) by reflectance spectrum measurement can be inspected nondestructively, There is an inconvenience that a dedicated inspection apparatus including a spectroscope and a darkroom is required. As a result, the configuration of the inspection apparatus becomes complicated. As a result, it was difficult to measure the film thickness of the power generation layer (i layer) with a simple apparatus configuration.
[0014]
  As described above, the conventional photovoltaic device has a non-destructive and simple device configuration.DepartureIt was difficult to inspect the thickness of the electric layer (i layer).
[0015]
  The present invention has been made to solve the above-described problems.ofThe purpose is a non-destructive and simple inspection device configuration, a photovoltaic deviceofIt is to provide a method for inspecting a photovoltaic device capable of detecting a film thickness of a power generation layer (i layer).
[0016]
[0017]
[0018]
[Means for Solving the Problems and Effects of the Invention]
  A photovoltaic device inspection method according to a first aspect of the present invention includes a step of applying an alternating voltage to a photovoltaic device having at least one pin junction, and a photovoltaic device to which the alternating voltage is applied.Detecting the admittance and measuring the film thickness of the i layer constituting the pin junction based on the admittance.
[0019]
  In the photovoltaic device inspection method according to the first aspect, as described above, an AC voltage is applied to the photovoltaic device having at least one pin junction, and the photovoltaic deviceAdmittanceBy detecting the film thickness of the i layer (power generation layer) that does not require light irradiation equipment and is nondestructive and forms a pin junctionTheCan be detected. As a result, the film thickness of the i layer of the photovoltaic device can be obtained with a non-destructive and simple inspection device configuration.TheCan be detected.
[0020]
[0021]
  In the photovoltaic device inspection method according to the first aspect, preferably, the i layer constituting the pin junction includes an amorphous silicon layer. If comprised in this way, in an amorphous photovoltaic apparatus etc., the film thickness of i layer which comprises a pin junction can be measured by the structure of a non-destructive and simple test | inspection apparatus. This point has been confirmed by experiments.
[0022]
[0023]
[0024]
  In the photovoltaic device inspection method according to the first aspect, preferably, the frequency of the alternating voltage applied to the photovoltaic device is 5 × 10 5.¹5 × 10 Hz or more^FiveIt is set to Hz or less. In this frequency range, since the admittance phase angle is close to 90 °, an approximate expression C = | Y | / ω (| Y | is an absolute value of admittance, ω Frequency) can be used. Thereby, the thickness of the i layer constituting the pin junction can be measured with a non-destructive and simple configuration of the inspection apparatus without degrading accuracy..
[0025]
[0026]
[0027]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0028]
  FIG. 1 is a basic circuit diagram of an inspection device used in a photovoltaic device inspection method according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between admittance (Y) and capacitor capacity (C). FIG. 3 is a diagram showing the correlation between the admittance phase angle (θ) and the measurement frequency (ω) of an amorphous silicon photovoltaic device having a normal pin junction without a short circuit. FIG. 4 is a diagram showing the relationship between the film thickness of the power generation layer (i layer) and the reciprocal of the capacitor capacity (C) obtained from the measurement method using a surface roughness meter. First, referring to FIGS. 1 to 4, a photovoltaic device inspection method according to an embodiment of the present invention.IsA method for measuring the film thickness of the i layer constituting the pin junction will be described.
[0029]
  As shown in FIG. 1, an output detection unit 1 including an impedance analyzer or an LCR meter is used in the film thickness measurement method for the i layer constituting the pin junction according to the present embodiment. The output detection unit 1 is used to measure the response output of a unit cell of a photovoltaic device having a pin junction when an AC voltage is applied. As shown in FIG. 1, the output detection unit 1 includes an AC power supply 2, a bias DC power supply 3, an ammeter 4, and a voltmeter 5. The AC power supply 2 is an example of the “AC voltage application unit” in the present invention. The AC power source 2, the bias DC power source 3, and the ammeter 4 are connected in series. The AC power supply 2 has a voltage of 0.05 V and a frequency of 10 Hz to 5 × 10.^FiveIt is possible to apply an alternating voltage of Hz. Further, a voltage of 0 to -1 V is always applied from the bias DC power supply 3 during response output measurement.
[0030]
  Further, as shown in FIG. 1, the unit cell of the photovoltaic device having a pin junction has a shunt resistance component (R_sh) And a capacitor capacity component (C). Generally, the capacitor capacity (C) is expressed as the following formula (1).
[0031]
  C = ε₀εS / d (1)
  Where C is the capacitor capacity (F), ε₀Is the vacuum dielectric constant (8.854 × 10^-12F / m²), Ε is the relative dielectric constant (F / m²), S is the electrode area (m²) (Here, the area of the electrode of the unit cell), d is the distance (m) between the electrodes (here, the film thickness of the power generation layer (i layer)).
[0032]
  When the above equation (1) is modified, it can be expressed as the following equation (2).
[0033]
  d = ε₀εS / C (2)
  Further, the relationship between the admittance (Y) and the capacitor capacity (C) is expressed as the following equation (3).
[0034]
  | Y | = {(ωC)²+ (1 / R_sh)²}^1/2      ... (3)
  Here, ω is the frequency of AC voltage applied during measurement (hereinafter referred to as measurement frequency) (Hz), R_shIs a shunt resistance (Ω).
[0035]
  Moreover, the relationship of the said Formula (3) can be expressed like FIG. In FIG. 2, θ is an admittance phase angle (°).
[0036]
  In the above formula (3), the shunt resistance (R_sh) Is sufficiently large, 1 / R_shIs close to 0, so 1 / R_shCan be ignored. In this case, the above equation (3) can be approximated as the following equation (4).
[0037]
  | Y | = ωC (4)
  When the approximate expression of the above expression (4) is modified, an approximate expression such as the following expression (5) is obtained.
[0038]
  C = | Y | / ω (5)
  Shunt resistance (R_sh) Is sufficiently large, the capacitor capacity (C) can be obtained from the measured admittance (Y) and the frequency (ω) of the alternating voltage at the time of measurement using the approximate expression (5).
[0039]
  In addition, shunt resistance (R_sh) Is sufficiently large, 1 / R_sh2 approaches 0, it can be seen from FIG. 2 that the admittance phase angle (θ) approaches 90 °. In this case, it can be seen that the approximate expression (5) can be applied with high accuracy.
[0040]
  In order to accurately measure the film thickness using the approximate expression (5), it is necessary to select an appropriate measurement frequency (ω) such that the admittance phase angle (θ) is close to 90 °. The appropriate measurement frequency is a frequency at which only the i layer as the power generation layer swings as a dielectric, and other semiconductor layers (p layer, n layer, transparent conductive film, etc.) swing as conductors. When the frequency is higher than an appropriate measurement frequency, carriers in the semiconductor layer other than the power generation layer (i layer) cannot follow the applied AC voltage, so that the semiconductor other than the power generation layer (i layer). The layer also behaves as a dielectric. In this case, since the capacitor capacity (C) is reduced, the admittance phase angle (θ) is also reduced from FIG. When the frequency is lower than the appropriate measurement frequency, carriers in the semiconductor layer other than the power generation layer (i layer) are injected into the power generation layer (i layer) following the applied AC voltage. All the semiconductor layers including the power generation layer (i layer) swing as conductors. In this case, shunt resistance (R_sh) Becomes smaller, the admittance phase angle (θ) also becomes smaller from FIG.
[0041]
  FIG. 3 shows the correlation between the admittance phase angle (θ) and the measurement frequency (ω) measured for an amorphous silicon photovoltaic device having a normal pin junction without a short circuit. Referring to FIG. 3, in an amorphous silicon photovoltaic device having a normal pin junction without a short circuit, the measurement frequency (ω) is about 3 × 10^FourAt Hz, the admittance phase angle (θ) showed a maximum value of about 89 °. Also, from FIG. 3, the appropriate measurement frequency range (ω) is 5 × 10¹Hz to 5 × 10^FiveIt is considered to be in the Hz range. When the measurement frequency (ω) is larger or smaller than this range, the admittance phase angle (θ) rapidly decreases. Therefore, the approximate expression (5) is applied to obtain the capacitor capacity (C). This is because it becomes difficult.
[0042]
  Also, in FIG. 4, 5 × 10¹Hz to 5 × 10^FiveThe reciprocal of the capacitor capacity (C) obtained from the admittance (Y) measured at an appropriate measurement frequency (ω) in the range of Hz using the above approximate expression (5), and measurement using a conventionally known surface roughness meter The relationship with the film thickness (d) of the power generation layer (i layer) measured by the method is shown. Referring to FIG. 4, it was found that the reciprocal of the capacitor capacity (C) and the film thickness (d) of the power generation layer (i layer) measured by the measuring method using the surface roughness meter showed a direct proportional relationship. . This direct proportionality coincides with the relation expressed in the above formula (2). Therefore, when the proportionality constant of the direct proportional relationship in FIG. 4 is A, it can be expressed as the following equation (6) from the above equation (2).
[0043]
  A = ε₀εS (6)
  For the above equation (6), ε₀The vacuum dielectric constant (8.854 × 10^-12F / m²In the amorphous silicon photovoltaic device having a normal pin junction without a short circuit, by substituting the measured value of the electrode area of the unit cell for S and the proportionality constant obtained from the direct proportional relationship of FIG. The relative dielectric constant ε = 13.3 to 13.4 was obtained.
[0044]
  By substituting the capacitor capacity (C) obtained by the approximate expression (5) and the relative dielectric constant (ε) obtained as described above into the above expression (2), the film of the power generation layer (i layer) The thickness (d) is required.
[0045]
  Next, the present inventionreferenceAmong the inspection methods for the photovoltaic device according to the embodiment, a method for detecting a short circuit component of the pin junction will be described.
[0046]
  If a short circuit occurs at the pin junction, the shunt resistor (R_sh) Decreases. Shunt resistance (R_sh) Decreases to 1 / R_shFrom FIG. 2, it can be seen that the admittance phase angle (θ) decreases. Thereby, a short circuit of the pin junction can be detected by monitoring the admittance phase angle (θ).
[0047]
  FIG. 5 shows the shunt resistance component (R_shFIG. 4 is a diagram showing a relationship between current (I) -voltage (V) curves and admittance phase angles (θ) of four pin junction amorphous silicon photovoltaic devices having different). Referring to FIG. 5, in the current (I) -voltage (V) curve, the slopes of straight lines B1, B2, B3 and B4 indicate the shunt resistance (R_sh). Shunt resistance (R_sh) Decreases, the admittance phase angle (θ) decreases rapidly. Also, from the experimental results, in a unit cell with an admittance phase angle (θ) of less than 80 °, there is a high possibility that there is a short-circuit failure in the pin junction due to pinholes or conduction at the separation portion of the unit cell. all right. In addition, short circuit failure due to conduction in the pinhole can be conducted between the metal electrode and the transparent conductive film (back side) by the melt of the metal electrode entering the pinhole generated during the creation of the photovoltaic device. This occurs due to the formation of a conducting part. In addition, a short circuit failure caused by conduction in the separation portion of the unit cell is caused by the scattering of metal electrodes on the inner wall of the separation portion of the unit cell when a single photovoltaic device is separated into a plurality of unit cells using a laser. The adhesion occurs due to the formation of a conductive portion that can conduct the metal electrode and the transparent conductive film (back surface side).
[0048]
  FIG. 6 is a schematic diagram showing a configuration of an inspection apparatus when the above-described inspection method for a photovoltaic apparatus is applied to an integrated photovoltaic apparatus including a plurality of unit cells. Next, with reference to FIG. 6, the configuration of an inspection apparatus for an integrated photovoltaic device according to an embodiment of the present invention will be described.
[0049]
  Of the present inventionreferenceThe inspection apparatus for an integrated photovoltaic device according to the embodiment includes a probe unit 6 and a measurement unit 7 as shown in FIG. The probe unit 6 and the measurement unit 7 are connected by a signal cable 8. The probe unit 6 includes a plurality of spring probes 9 that can simultaneously contact the electrodes of the plurality of unit cells 100 a of the integrated photovoltaic device 100. The measurement unit 7 includes a controller, a contact changeover switch, a storage device, an LCR meter, and a programmable power supply. The contact changeover switch is provided to perform switch control for sequentially measuring between the pair of spring probes 9. The storage device is provided to record the measured film thickness value and the like. The LCR meter is provided for measuring an admittance (Y) and an admittance phase angle (θ) of the unit cell 100a when an AC voltage is applied to the unit cell 100a. The LCR meter is an example of the “AC voltage application unit” and the “output detection unit” in the present invention. The programmable power supply is provided to apply a pulsed reverse bias voltage (voltage 0.5 V to 5 V, current limit 0.1 A, application time 0.1 second to 1 second).
[0050]
  Next, the operation of the inspection apparatus for the integrated photovoltaic device will be described with reference to FIG. In this inspection apparatus for an integrated photovoltaic device, the film thickness of the power generation layer (i layer) is measured and the short-circuit component of the pin junction is detected, and when the short-circuit component of the pin junction is detected, the short-circuit is detected. Repair the defect.
[0051]
  First, contacts are made simultaneously to the electrodes of the plurality of unit cells 100 a of the integrated photovoltaic device 100 by the plurality of spring probes 9 of the probe unit 6. Then, an AC voltage is applied to the plurality of unit cells 100 a by the LCR meter of the measurement unit 7. As a response to the applied AC voltage, an electric signal is sent from all the unit cells 100 a to the measurement unit 7 via the spring probe 9 and the probe unit 6. At this time, only the electrical signal between the pair of adjacent spring probes 9 is sent to the measuring unit 7 by the contact changeover switch, and the switch control is performed so that the electrical signal between the adjacent spring probes 9 is sequentially sent. Is called. Since the pair of spring probes 9 corresponds to one unit cell 100a, the response output (electric signal) of each unit cell 100a with respect to the applied AC voltage is detected by switch control of the contact changeover switch.
[0052]
  Based on the detected response output of each unit cell 100a, the LCR meter measures the admittance (Y) and the admittance phase angle (θ) of each unit cell 100a. When the measured admittance phase angle (θ) is 80 ° or more, the film thickness (d) of the power generation layer is calculated by using the above formula (2) and the above approximate formula (5). Then, the calculated value of the power generation layer thickness (d) is recorded in the storage device. Then, the measurement of the adjacent unit cell 100a is performed subsequently.
[0053]
  Here, in the present embodiment, when the measured admittance phase angle (θ) is less than 80 °, it is determined that the short circuit is defective, and the pulsed reverse bias voltage ( Voltage 0.5V to 5V, current limit 0.1A, application time 0.1 second to 1 second). As a result, the conduction part formed by the pinhole or the separation part of the unit cell 100a is burned out, or the conduction part is insulated by oxidation, thereby repairing the short circuit defect. The admittance phase angle (θ) is again measured by the LCR meter for the unit cell to which the reverse bias voltage is applied. If the admittance phase angle (θ) becomes 80 ° or more, the film thickness (d) of the power generation layer (i layer) is calculated, and then the value of the film thickness (d) of the power generation layer is recorded in the storage device. When the admittance phase angle (θ) does not exceed 80 °, the pulsed reverse bias voltage is applied again. If the application of the pulsed reverse bias voltage and the measurement of the admittance phase angle (θ) are repeated several times, if the admittance phase angle (θ) does not become 80 ° or more, the measurement shifts to the measurement of the adjacent unit cell 100a. .
[0054]
  FIG. 7 compares the admittance phase angle (θ) distribution between the initial state of the integrated photovoltaic device having many short-circuit defects and the pulse voltage processing using the inspection device shown in FIG. FIG. FIG. 8 is a diagram showing the distribution of the film thickness of the power generation layer (i layer) calculated from the admittance (Y) for the integrated photovoltaic device having many short-circuit defects used in FIG.
[0055]
  Referring to FIG. 7, in the initial state, the admittance phase angle (θ) of the integrated stage (unit cell) showing a low value of admittance phase angle (θ) is improved after the pulse voltage processing. I understand. That is, it can be seen that the short-circuit defective portion is repaired. The output power of this integrated photovoltaic device increased from about 23.5 W in the initial state to 26.3 W after the pulse voltage process, an improvement of about 12%.
[0056]
  In addition, referring to FIG. 8, the film thickness (d) of the power generation layer (i layer) calculated from the measured value of admittance (Y) shows a value in the vicinity of 300 nm. This value almost coincides with the design film thickness of the power generation layer (i layer). In addition, when the number of integrated stages is around 1 to 15 and around 65 to 80, the film thickness tends to be slightly smaller than 300 nm. This tendency coincides with the tendency of the actually measured value of the film thickness. In FIG. 8, an integrated stage (unit cell) in which the thickness of the power generation layer (i layer) is locally small can be seen. It can be seen from FIG. 7 that this integrated stage (unit cell) is an integrated stage (unit cell) in which the admittance phase angle (θ) has not improved much even when pulse voltage processing is performed. That is, in this integrated stage (unit cell), it is considered that the short circuit failure of the pin junction was not repaired even when the pulse voltage process was performed. Therefore, since accurate measurement is not performed in this integrated stage (unit cell), the value of the locally small film thickness in FIG. 8 is the film thickness (d) of the actual power generation layer in the integrated stage. It is thought that it does not show.
[0057]
  BookreferenceIn the embodiment, as described above, the AC voltage is applied to the photovoltaic device having at least one pin junction, and the admittance (Y) and the admittance phase angle (θ) of the photovoltaic device are detected to Irradiation equipment is not required, and it is non-destructive.pA short circuit component of the in-junction can be detected. In this way, with a non-destructive and simple inspection device configuration,pA short circuit component of the in-junction can be detected.
[0058]
  Also bookreferenceIn the embodiment, by applying a bias voltage to the pin junction in which the short-circuit component is detected, the short-circuit failure is repaired, so that the pin junction in which the short-circuit failure is detected can be repaired in the inspection process.
[0059]
  Also bookreferenceIn the embodiment, the frequency of the AC voltage applied to the photovoltaic device is 5 × 10¹5 × 10 Hz or more^FiveBy setting the frequency to be equal to or lower than Hz, the admittance phase angle becomes close to 90 °. Therefore, the approximate expression C = | Y | / ω for obtaining the capacitance C can be used without reducing the accuracy. Thereby, the film thickness of i layer which comprises a pin junction can be measured by the structure of a non-destructive and simple test | inspection apparatus, without reducing precision. In addition, within the above frequency range, the shunt resistance R generated when there is a short circuit failure of the pin junction._shCan be clearly detected by monitoring changes in the admittance phase angle. As a result, the short-circuit component of the pin junction can be reliably detected with a non-destructive and simple configuration of the inspection apparatus.
[0060]
  Also bookreferenceIn the embodiment, by providing an AC voltage to the photovoltaic device having a pin junction and providing a measurement unit 7 including an LCR meter that detects the admittance and admittance phase angle of the photovoltaic device to which the AC voltage is applied, It is possible to detect the output characteristics of the photovoltaic device such as the film thickness of the i layer constituting the pin junction and the short-circuit component of the pin junction without requiring light irradiation equipment and the like. Thereby, the output characteristic of the photovoltaic device can be detected with a non-destructive and simple inspection device configuration.
[0061]
  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.
[0062]
[0063]
  In the inspection apparatus for an integrated photovoltaic device shown in FIG. 6, an AC voltage is applied and an LCR meter is used to detect an admittance and an admittance phase angle. However, the present invention is not limited to this. Other devices having similar functions such as an impedance analyzer may be used.
[0064]
  Moreover, in the said embodiment, although the inspection apparatus and inspection method of this invention were applied with respect to the photovoltaic apparatus in which i layer which comprises a pin junction was formed of the amorphous silicon layer, this invention is not limited to this Alternatively, the present invention may be applied to a photovoltaic device in which the i layer is formed of a layer made of a material other than amorphous silicon. For example, the present invention may be applied to a photovoltaic device in which the i layer is formed of a crystalline silicon layer or the like.
[Brief description of the drawings]
FIG. 1 is a basic circuit diagram of an inspection apparatus used in a photovoltaic apparatus inspection method according to an embodiment of the present invention.
FIG. 2 is a diagram showing the relationship between admittance (Y) and capacitor capacity (C).
FIG. 3 is a diagram showing a correlation between an admittance phase angle (θ) and a measurement frequency (ω) of an amorphous silicon photovoltaic device having a normal pin junction without a short circuit.
FIG. 4 is a diagram showing the relationship between the film thickness of the power generation layer (i layer) and the reciprocal of the capacitor capacity (C) obtained from a measurement method using a surface roughness meter.
FIG. 5 Shunt resistance component (R_shFIG. 4 is a diagram showing a relationship between current (I) -voltage (V) curves and admittance phase angles (θ) of four pin junction amorphous silicon photovoltaic devices having different).
FIG. 6 is a schematic view showing a configuration of an inspection apparatus when the above-described inspection method for a photovoltaic apparatus is applied to an integrated photovoltaic apparatus including a plurality of unit cells.
FIG. 7 compares the admittance phase angle (θ) distribution between the initial state of an integrated photovoltaic device having many short-circuit defects and that after pulse voltage processing is performed using the inspection device shown in FIG. FIG.
8 is a diagram showing the distribution of the film thickness of the power generation layer (i layer) calculated from the admittance (Y) for the integrated photovoltaic device having many short-circuit defects used in FIG.
[Explanation of symbols]
  1 Output detector
  2 AC power supply (AC voltage application unit)
  3 DC power supply for bias
  4 Ammeter
  5 Voltmeter
  6 Probe unit
  7 Measurement unit
  8 Signal cable
  9 Spring probe
  100 Integrated photovoltaic device
  100a unit cell

Claims (3)

Applying an alternating voltage to a photovoltaic device having at least one pin junction;
A method for inspecting a photovoltaic device , comprising: detecting an admittance of the photovoltaic device to which the AC voltage is applied, and measuring a film thickness of an i layer constituting the pin junction based on the admittance .   The photovoltaic device inspection method according to claim 1, wherein the i layer constituting the pin junction includes an amorphous silicon layer. The method for inspecting a photovoltaic device according to claim 2, wherein the frequency of the alternating voltage applied to the photovoltaic device is set to 5 x 10 ¹ Hz or more and 5 x 10 ⁵ Hz or less.

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