JP2012195460A - Solar battery spectral sensitivity characteristic measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow solar battery spectral sensitivity characteristic measurement of higher precision by radiating bias light to a soler battery under the condition equal to monochromatic light as much as possible, and raising precision in holding position of the solar battery.SOLUTION: A beam splitter 4, provided to a point at which a monochromatic light optical system 1 intersects with a bias light optical system 3, causes a part of bias light to be reflected while a part of monochromatic light to transmit so that both the bias light and the monochromatic light are advanced in the same direction, to be incident on a solar battery S at the same angle. A battery position monitor 6 radiates laser light obliquely from both sides, with the optical axis of monochromatic light incident on the surface of the solar battery S in between. It radiates in such a manner that beam spots of two laser lights overlap each other on the surface of the solar battery S when the solar battery S is held at a predetermined position by a battery holding part 2.

Description

  The invention of the present application relates to an apparatus for measuring spectral sensitivity characteristics of a solar cell, and relates to a solar cell spectral sensitivity characteristic measuring apparatus that measures spectral sensitivity characteristics such as power generation characteristics by irradiating the surface of the solar cell with monochromatic light. Is.

As an environmentally friendly power generation technology, societal attention to solar power generation is very high, and there are remarkable things such as the spread of solar power generation devices to ordinary households and the support measures by the government.
There are several types of solar power generation, such as a crystal type and a thin film type, and intensive research and development is being carried out for the purpose of improving power generation efficiency. In research and development of solar cells, it is indispensable to investigate the spectral sensitivity characteristics of solar cells. The solar cells are irradiated with light that has been split into monochromatic light by a spectroscopic element, and characteristics such as power generation characteristics for each wavelength are measured It is essential to measure. For this reason, an apparatus for measuring spectral sensitivity characteristics by irradiating a solar cell with light that has been split into monochromatic light by a spectroscopic element has been developed and used.

  In the above-described measurement of spectral sensitivity characteristics of a solar cell that is irradiated with monochromatic light, it is necessary to irradiate bias light in order to bring the measurement state closer to the use state. The monochromatic light is configured to enter perpendicularly to the surface of the solar cell, while the bias light is configured to enter the surface of the solar cell obliquely. However, if the difference between the incident angle of the monochromatic light and the incident angle of the bias light is increased, a problem arises in terms of measurement accuracy. That is, the bias light includes light of all wavelengths, but some of the light of these wavelengths changes the amount of incident light into the solar cell depending on the angle (has angle dependency). For this reason, if the incident angle of the bias light is significantly different from the incident angle of the monochromatic light, the measurement is performed in a state close to the actual use state. For this reason, JIS stipulates that the incident angle of the bias light with respect to the incident angle of the monochromatic light is within 20 degrees.

JP 2008-298471 A

  In the solar cell spectral sensitivity characteristic measurement described above, in order to improve the measurement accuracy, it is necessary to irradiate the solar cell with the bias light under the same conditions as the monochromatic light as much as possible, or to increase the accuracy of the solar cell holding position. ing. The invention of the present application has been made to solve these problems, and by irradiating the solar cell with bias light under the same conditions as monochromatic light as much as possible, or by increasing the accuracy of the holding position of the solar cell, It has technical significance that enables measurement of spectral sensitivity characteristics with high accuracy.

In order to solve the above-mentioned problem, the invention of the solar cell spectral sensitivity characteristic measuring device according to claim 1 of the present application includes an optical system for monochromatic light for irradiating the surface of the solar cell with monochromatic light, and an optical system for monochromatic light. A battery holding unit for holding the solar cell at a predetermined position in the traveling direction of monochromatic light on the optical path, and a bias light optical system for irradiating the solar cell held at the predetermined position by the battery holding unit with bias light. ,
A beam splitter is provided at a location where the monochromatic light optical system and the bias light optical system intersect, and the beam splitter transmits a part of the monochromatic light while reflecting a part of the bias light. The monochromatic light is made to travel in the same direction and enter the solar cell at the same angle, or a part of the monochromatic light is reflected while transmitting a part of the bias light so that the bias light and the monochromatic light are directed in the same direction. It has a configuration in which it is made to enter and enter the solar cell at the same angle.
In order to solve the above-mentioned problem, the invention of the solar cell spectral sensitivity characteristic measuring device according to claim 2 comprises: an optical system for measuring light for irradiating the surface of the solar cell with monochromatic light; A battery holder that holds the solar cell at a predetermined position in the traveling direction of monochromatic light on the road, and a battery position monitor that monitors whether the solar cell is held at the predetermined position;
The battery position monitor is composed of a laser irradiation system that irradiates laser light obliquely from the front of the solar cell held at the predetermined position when the side on which the monochromatic light is incident is the front side. Laser light is irradiated from both sides across the optical axis of monochromatic light incident on the surface of the battery. When the solar battery is held at the predetermined position, two laser lights are used on the surface of the solar battery. It has the structure that it irradiates so that a beam spot may overlap.

As described below, according to the first aspect of the present invention, a beam splitter is provided at the intersection of the monochromatic light optical system and the bias light optical system so that the monochromatic light and the bias light are at the same angle. Therefore, the influence of wavelength angle dependency is eliminated, and the characteristics when monochromatic light is incident under the same conditions as the bias light can be measured.
In addition, according to the second aspect of the present invention, the solar cell holding position can be monitored by the battery position monitor and measured after being held at a predetermined position, so that measurement with high accuracy in terms of position reproducibility is possible. Yes.

It is the figure which showed schematic structure of the solar cell spectral sensitivity characteristic measuring apparatus which concerns on embodiment of this invention. It is the plane schematic shown about operation | movement of the battery position monitor.

Next, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described.
FIG. 1 is a diagram showing a schematic configuration of a solar cell spectral sensitivity characteristic measuring apparatus according to an embodiment of the present invention. The solar cell spectral sensitivity characteristic measuring apparatus shown in FIG. 1 is a monochromatic light optical system 1 for irradiating the surface of a solar cell S with monochromatic light, and in the traveling direction of monochromatic light on the optical path of the monochromatic light optical system 1. A battery holding unit 2 that holds the solar cell S at a predetermined position, and a bias light optical system 3 that irradiates the solar cell S held at the predetermined position by the battery holding unit 2 with bias light.

  The monochromatic light optical system 1 is a Zellnie Turner type optical system using a flat diffraction grating 11 as a spectroscopic element, and includes a monochromatic light source 12, an entrance slit 13, and first and second concave mirrors 14. , 15, a diffraction grating (grating) 11, an exit slit 16, a condenser lens 17 that condenses the light that has passed through the exit slit 16 and irradiates the solar cell S, and the like. The light from the monochromatic light source 12 enters through the entrance slit 13, is converted into parallel light by the first concave mirror 14, and is then applied to the diffraction grating 11. The light reflected by the diffraction grating 11 becomes monochromatic light, is reflected by the second concave mirror 15, is condensed again by the condenser lens 17 through the exit slit 16, and enters the solar cell S.

  In the present embodiment, a diffraction grating 11 is used as a spectroscopic element, and a drive system 18 for the diffraction grating 11 is attached. The drive system 18 adjusts the attitude (arrangement angle on the optical axis) of the diffraction grating 11 so that light of a specified wavelength is output as monochromatic light. When the spectral sensitivity characteristic in a certain wavelength range is measured, the drive system 18 sequentially changes the attitude of the diffraction grating 11 so that monochromatic light is sequentially output for each wavelength width defined by the resolution in the wavelength range (wavelength sweep). To do).

  On the other hand, the bias light optical system 3 includes a bias light source 31, a collimator element 32 that collimates the light from the bias light source 31, and a bias filter 33. As the bias light source 31, a light source having a light emission spectrum distribution close to sunlight, such as a xenon lamp, is used. The bias filter 33 is a filter for bringing the spectrum closer to the actual use state. For example, an air mass filter that adjusts the spectrum distribution according to the latitude of the place of use is used. The monochromatic light optical system 1 and the bias light optical system 3 are provided with a shutter (not shown), and the measurement start and stop are controlled by opening and closing the shutter.

  In the present embodiment, the beam splitter 4 is provided to cause the monochromatic light and the bias light to enter the solar cell S at the same angle (on the same axis). As shown in FIG. 1, the beam splitter 4 is provided at a position where the optical axis of the monochromatic light optical system 1 and the optical axis of the bias light optical system 3 intersect at right angles, and transmits part of the monochromatic light. It is made to direct to the solar cell S, and a part of bias light is reflected and it is made to direct to the solar cell S.

  The battery holding unit 2 holds the solar battery S at a condensing position by the condensing lens 17. The battery holding unit 2 includes a battery base 21 on which the solar battery S is placed, a fixture (not shown) such as a clamp that fixes the solar battery S on the battery base 21, and an adjustment mechanism 22 that finely adjusts the position of the battery base 21. Etc. The adjusting mechanism 22 employs a precision screw mechanism such as a micrometer so that the battery base 21 can be displaced in a direction along the optical axis and in a direction perpendicular to the optical axis. The directions perpendicular to the optical axis are preferably two directions orthogonal to each other in a plane perpendicular to the optical axis (xy directions when the optical axis is the z direction).

  In addition, the apparatus includes a measurement circuit unit 5 that measures spectral sensitivity characteristics (such as current characteristics due to photovoltaic power) in the solar cell S that is held by the battery holding unit 2 and irradiated with monochromatic light and bias light. . The measurement circuit unit 5 includes a circuit for measuring a voltage generated at a load end connected to the solar cell S and a current flowing through the load, a circuit for improving an SN ratio, an output circuit for outputting a measurement result, and the like.

On the other hand, as shown in FIG. 1, the solar cell spectral sensitivity characteristic measuring apparatus of the present embodiment includes a battery position monitor 6 that monitors whether the solar battery S is held at a predetermined position. In this embodiment, since monochromatic light is condensed and used by the condensing lens 17, the predetermined position monitored by the battery position monitor 6 is a condensing position by the condensing lens 17. As shown in FIG. 1, the battery position monitor 6 comprises a laser irradiation system that irradiates laser light obliquely from the front of the solar cell S held at the condensing position, when the side on which the monochromatic light is incident is the front side. It is. The laser irradiation system irradiates laser light from both sides across the optical axis of monochromatic light, and is configured by arranging laser oscillators 61 and 62 obliquely at the upper right and obliquely upper left of the condensing position.
Each of the laser oscillators 61 and 62 is a visible light laser oscillator such as a He—Ne laser or a visible light semiconductor laser. The two laser oscillators 61 and 62 are provided at a position where the laser beams are overlapped at the condensing position.

FIG. 2 is a schematic plan view showing the operation of the battery position monitor 6. FIG. 2 (1) shows a state in which the solar cell S is not correctly positioned at the condensing position, and (2) shows a state in which it is correctly positioned.
When the solar cell S is placed on the battery base 21 and the laser irradiation system is operated, the beam spots B and B ′ due to the laser light appear on the surface of the solar cell S. When the surface of the solar cell S is not correctly positioned at the condensing position, two beam spots B and B ′ appear separately as shown in FIG. When the adjustment mechanism 22 is operated to displace and finely adjust the battery base 21 in the direction of the optical axis, and the surface of the solar battery S is correctly positioned at the condensing position, two beam spots B, It appears that B 'has just overlapped to form one beam spot. When the incident angle of the laser beam (angle with respect to the plane perpendicular to the optical axis, indicated by θ in FIG. 1) is 30 to 60 degrees (more preferably 40 to 50 degrees), the overlapping of the beam spots B and B ′ Since it is easy to visually recognize, it is preferable.

  The entire surface of the solar cell S is the surface to be measured and may be incident anywhere, but only a specific area of the surface of the solar cell S is the surface to be measured. In some cases, it is necessary to make it incident. For example, this is a case where the solar cell S is partitioned into several areas, and the spectral sensitivity characteristics must be measured for each. In this case, the adjustment mechanism 22 is operated to displace the solar cell S in the direction perpendicular to the optical axis, and the measurement surface is positioned at the condensing position (on the optical axis). For example, as shown in FIG. 2 (3), when the solar cell S is divided into three areas and the central area is the surface to be measured, the beam spots B and B ′ are as described above in that area. The adjusting mechanism 22 is operated so as to overlap one.

  The operation of the solar cell spectral sensitivity characteristic measurement according to this embodiment having the above-described configuration will be described below. When performing the measurement, the solar cell S is placed on the battery base 21 as described above, and the battery position monitor 6 is operated to place the surface of the solar cell S at a predetermined position (in this embodiment, the condensing position by the condensing lens 17). ). Thereafter, the laser oscillators 61 and 62 of the battery position monitor 6 are stopped, and the monochromatic light source 12 and the bias light source 31 are turned on. After operating the driving system 18 of the diffraction grating 11 as a spectroscopic element to control the diffraction grating 11 to a posture in which predetermined monochromatic light is output, the shutters (not shown) arranged in the optical systems 1 and 3 are opened, Measure. Monochromatic light and bias light are incident on the solar cell S, and a photovoltaic force is generated, and each characteristic is measured by the measurement circuit unit 5.

  As an example, a half mirror can be used as the beam splitter 4 used for integrating the monochromatic light and the bias light. However, in some cases, the transmittance (reflectance) may be 50%. For example, the reflectance may be 20% (80% transmittance) so that the monochromatic light and the bias light have a predetermined ratio. In some cases, the reflectance is 70% (transmittance of 30%).

  According to the solar cell spectral sensitivity characteristic measuring apparatus of the present embodiment related to the above-described configuration and operation, the beam splitter 4 is provided at the intersection of the monochromatic light optical system 1 and the bias light optical system 3, and the monochromatic light and the bias light are provided. Are incident on the solar cell S at the same angle, the influence of wavelength angle dependency is eliminated, and the characteristics when monochromatic light is incident under the same conditions as the bias light can be measured.

  Further, since the solar cell S can be arranged at a predetermined position while the arrangement position is monitored by the battery position monitor 6, measurement with high accuracy can be performed in terms of position reproducibility. In the above-described embodiment, the condensing position by the condensing lens 17 is a predetermined position. However, for example, even when collimation is performed using a collimator element (collimator lens or collimator mirror), perfect parallelism is desired. Therefore, it is necessary to perform measurement while always holding the solar cell S at the same position, and the position set in this way is the predetermined position.

Next, the configuration of another embodiment will be described.
In the embodiment shown in FIG. 1, a part of the monochromatic light is transmitted while reflecting a part of the bias light, and the bias light and the monochromatic light are caused to enter the solar cell S in the same direction. The beam splitter 4 may be configured to reflect a part of the monochromatic light while transmitting a part of the bias light and to make the bias light and the monochromatic light travel in the same direction and enter the solar cell S. Also in this case, for example, the transmittance is set to 20% (80% reflectivity) so that the monochromatic light and the bias light have a predetermined ratio, or conversely, the transmittance is set to 70% (30% reflectivity). There is a case.

Further, the battery position monitor 6 may be configured such that the laser irradiation system includes only one laser oscillator. In this case, the optical system is configured so that laser light from one laser oscillator is divided by a beam splitter and reaches a predetermined position on the optical axis at the same position and angle as shown in FIG.
In the configuration of each of the embodiments described above, two of the monochromatic light source 12 and the bias light source 31 are used, but a single light source may be used. In this case, it is divided into two parts using a beam splitter, and one of them is spectrally used via a spectroscopic element as described above.

Further, as the monochromatic light optical system, an arbitrary system such as an Evert type or a Fastie Evert type other than the above-mentioned Zellney Turner type can be adopted. Employing the optical system described in Japanese Patent Application Laid-Open No. 2000-55733 is preferable because the aberration is small and the resolution is high. In addition, it is also possible to measure each wavelength simultaneously by holding the solar cell at a position where each wavelength region is incident (or arranging each area of one solar cell) without scanning the diffraction grating as the spectroscopic element. Is possible.
It is not an essential requirement that the battery base has a structure in which the solar battery is placed and held on the upper surface. The structure in which the battery base is placed vertically and the solar battery is held upright is measured. Sometimes adopted. Or a solar cell may be hold | maintained on the lower surface of a battery stand.

DESCRIPTION OF SYMBOLS 1 Optical system for monochromatic light 11 Diffraction grating 12 Light source for monochromatic light 2 Battery holding part 21 Battery stand 22 Adjustment mechanism 3 Optical system for bias light 31 Light source for bias light 4 Beam splitter 5 Measuring circuit unit 6 Battery position monitor 61 Laser oscillator 62 Laser oscillator

Claims (2)

An optical system for monochromatic light for irradiating the surface of the solar cell with monochromatic light, a battery holding unit for holding the solar cell at a predetermined position in the traveling direction of the monochromatic light on the optical path of the optical system for monochromatic light, and a battery holding unit And a bias light optical system for irradiating the solar cell held in a predetermined position with a bias light,
A beam splitter is provided at a location where the monochromatic light optical system and the bias light optical system intersect, and the beam splitter transmits a part of the monochromatic light while reflecting a part of the bias light. The monochromatic light is made to travel in the same direction and enter the solar cell at the same angle, or a part of the monochromatic light is reflected while transmitting a part of the bias light so that the bias light and the monochromatic light are directed in the same direction. A solar cell spectral sensitivity characteristic measuring device characterized in that the solar cell is made to enter the solar cell at the same angle. An optical system for measuring light for irradiating the surface of the solar cell with monochromatic light, a battery holding unit for holding the solar cell at a predetermined position in the traveling direction of the monochromatic light on the optical path of the measuring optical system, and a solar at the predetermined position A battery position monitor that monitors whether the battery is held,
The battery position monitor is composed of a laser irradiation system that irradiates laser light obliquely from the front of the solar cell held at the predetermined position when the side on which the monochromatic light is incident is the front side. Laser light is irradiated from both sides across the optical axis of monochromatic light incident on the surface of the battery. When the solar battery is held at the predetermined position, two laser lights are used on the surface of the solar battery. A solar cell spectral sensitivity characteristic measuring apparatus characterized by irradiating a beam spot so as to overlap.

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