JP2013098348A - Pseudo sunlight irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an error generation in a characteristic value of an object to be measured.SOLUTION: A pseudo sunlight irradiation device 100 comprises between a halogen light source 1 and a wavelength selection member 5 a light guide member 3 whose length is such that an absorption ratio against infrared light of a wavelength longer than or equal to a mid-infrared is 95% or higher.

Description

  The present invention relates to a pseudo-sunlight irradiation device that emits pseudo-sunlight.

  The importance of solar cells as a clean energy source is recognized, and the demand for solar cells is increasing. Solar cells are used in a wide range of fields, from power energy sources for large equipment to small power sources for precision electronic equipment. In order for solar cells to be widely used in various fields, various inconveniences are expected on the side of using solar cells unless the characteristics of the solar cells, particularly the output characteristics, are measured accurately. For this reason, the technique which can irradiate a large area with artificial high precision artificial sunlight which can be utilized for the test | inspection of a solar cell, a measurement, and an experiment is calculated | required.

  The main elements required for simulated sunlight are that the emission spectrum of simulated sunlight is close to that of standard sunlight (established by Japanese Industrial Standards), and that the illuminance of simulated sunlight is comparable to that of standard sunlight. It is. Therefore, a simulated sunlight irradiation device has been developed as a device for irradiating such simulated sunlight. The pseudo-sunlight irradiation device is generally used to measure the amount of power generated by a solar cell by irradiating artificial light with a uniform illuminance (pseudo-sunlight) on the light receiving surface of the solar cell.

  Patent Document 1 discloses a simulated solar irradiation device (solar simulator) in which halogen lamps and xenon lamps are installed in adjacent individual chambers. Specifically, this simulated solar light irradiation device includes a dedicated optical filter in the upper open portion of each lamp. Thereby, the artificial sunlight by lighting of a lamp | ramp is irradiated from the downward direction with respect to the light-receiving surface of a solar cell. Furthermore, this pseudo-sunlight irradiation apparatus is provided with a reflecting plate in the room where each lamp is installed. Thereby, the illuminance unevenness of the lamp is adjusted. It also describes that a cooling device such as a suction fan is provided on the side wall so as to communicate with each chamber in which each lamp is installed.

JP 2002-0487704 A (publication date: February 15, 2002)

  However, in the technique described in Patent Document 1, light having a long wavelength such as a mid-infrared ray or a far-infrared region contained in light emitted from a lamp is irradiated to a solar cell that is a measurement object. When such a long wavelength light is irradiated on the solar cell, the temperature value of the solar cell rises and the characteristic value such as the IV characteristic of the solar cell changes, resulting in an error in the measurement result. There's a problem.

  The present invention has been made in view of the above-described problems, and an object thereof is to realize a simulated solar light irradiation apparatus that can suppress the occurrence of an error in the characteristic value of an object to be measured.

  The simulated solar light irradiation apparatus of the present invention includes a first light source and a second light source, light having a longer wavelength than a predetermined wavelength among light from the first light source, and the predetermined light among light from the second light source. A pseudo-sunlight irradiating device that irradiates the light mixed by the mixing member as pseudo-sunlight, comprising a mixing member that mixes light having a wavelength shorter than the wavelength, wherein the first light source and the mixing member The light guide member having a length such that the absorptance with respect to infrared rays having wavelengths longer than or equal to the middle infrared ray is 95% or more is provided.

  According to said structure, the light guide member which is the length from which the absorptivity with respect to the infrared rays of a wavelength more than a mid-infrared becomes 95% or more is provided between a 1st light source and the said mixing member. As a result, most of the infrared light having a wavelength equal to or greater than the mid-infrared wavelength of the light emitted from the first light source is absorbed by the light guide member, thereby reducing the amount of infrared light having a wavelength equal to or greater than the mid-infrared included in the pseudo-sunlight. be able to. As a result, it is possible to suppress measurement errors caused by temperature rise of the object to be measured due to light having a long wavelength such as mid-infrared or higher.

  Furthermore, in the simulated solar lighting device of the present invention, the light guide member is preferably borosilicate crown glass. Borosilicate crown glass has a tendency that the light absorption rate increases as the wavelength increases from near mid-infrared. In the borosilicate crown glass, the absorptance with respect to most of the infrared rays over the mid-infrared when propagating a distance of 10 mm is 90% or more (transmittance less than 10%). Thereby, even if it is a light guide member of comparatively short length, the infrared rays of a wavelength more than a mid-infrared can be easily absorbed with a light guide member. The first light source is, for example, a halogen lamp.

  Furthermore, in the simulated solar lighting device of the present invention, a distance between an incident surface on the light guide member on which light from the first light source is incident and an exit surface on which light is emitted to the mixing member is the incident surface. It is preferable that the width is 6 times or more.

  According to said structure, the absorption factor of the infrared rays of the wavelength more than the middle infrared by a light guide member can be raised, and the quantity of the infrared rays of the wavelength more than the middle infrared contained in pseudo-sunlight can be reduced further. .

  Furthermore, in the simulated solar lighting device of the present invention, it is preferable that the first light source has an arc tube, and the thickness of the light guide member is not less than the diameter of the arc tube. Furthermore, the thickness of the light guide member is more preferably 1.5 times or more the diameter of the arc tube.

  According to the above configuration, most of the light emitted from the first light source can be incident on the light guide member, and the amount of light (stray light) incident on the object to be measured without passing through the light guide member can be reduced. Can be made. Such stray light affects the characteristic value of the object to be measured. Therefore, the measurement error of the object to be measured can be further reduced by reducing the amount of stray light.

  In addition, the simulated sunlight irradiation device of the present invention includes a light source, a light guide plate that irradiates the object to be measured with simulated sunlight using light from the light source, and a direction of the light guide plate that emits light emitted from the light source. A pseudo-sunlight irradiating device including a light guide member for guiding the light to the measurement object, wherein the light guide member has a mid-infrared ray in order to reduce the amount of incident infrared rays having a wavelength equal to or greater than the mid-infrared ray to the object to be measured. It has a function of absorbing part of the infrared component having the above wavelength.

  Moreover, the simulated sunlight irradiation device of the present invention includes a light source, an optical member that adjusts a spectrum of light from the light source, a light guide plate that irradiates simulated sunlight using light adjusted by the optical member, A pseudo-sunlight irradiating device comprising a light guide member for causing the light emitted from the light source to enter the optical member, wherein the light guide member is a mid-infrared ray in the light emitted from the light source A part of the infrared component having the above wavelength is absorbed before entering the optical member.

  Even with the above configuration, a part of infrared light having a wavelength equal to or greater than the mid-infrared wavelength of the light emitted from the light source is absorbed by the light guide member, thereby reducing the amount of infrared light having a wavelength equal to or greater than the mid-infrared included in the pseudo-sunlight. Can be made. As a result, it is possible to suppress a measurement error caused by a temperature rise of the object to be measured due to light having a long wavelength longer than the mid-infrared.

  According to the simulated sunlight irradiation device of the present invention, there is an effect that it is possible to suppress the occurrence of an error in the characteristic value of the object to be measured.

It is a schematic diagram which shows the principal part structure of the simulated sunlight irradiation apparatus of one Embodiment which concerns on this invention. It is a schematic diagram which shows a part of light introduction part in the said simulated sunlight irradiation apparatus. It is a figure which shows the transmittance | permeability with respect to the light which injected into the wavelength selection member with the incident angle of 45 degree | times. It is a schematic diagram which shows a part of modification of the light introduction part in the said pseudo | simulation sunlight irradiation apparatus. It is a perspective view which shows the structure of the simulated sunlight irradiation apparatus of one Example which concerns on this invention. It is a figure which shows schematic structure of the halogen light source of another Example which concerns on this invention. It is a perspective view which shows the detailed structure of the light irradiation apparatus of another Example which concerns on this invention. It is a perspective view which shows the detailed structure of the said light irradiation apparatus seen from another angle. It is a perspective view which shows the structure of a part of halogen light source periphery in the said simulated sunlight irradiation apparatus.

[Embodiment 1]
(Configuration of pseudo-sunlight irradiation device 100)
An embodiment according to the present invention will be described with reference to the drawings. First, a simulated sunlight irradiation apparatus (light irradiation apparatus) 100 that irradiates the object 21 with simulated sunlight will be described in detail with reference to FIG. FIG. 1 is a schematic diagram showing the main configuration of the simulated solar light irradiation apparatus 100. Simulated sunlight is a kind of artificial light and has an emission spectrum close to the emission spectrum of natural light (sunlight). The simulated sunlight irradiating apparatus 100 of this embodiment irradiates a measured object (irradiated body) 21 such as a solar cell using synthetic light of xenon light and halogen light as simulated sunlight.

  As shown in FIG. 1, the simulated solar light irradiation device 100 includes a light introduction unit 20 that introduces light, a light guide plate 8, a light extraction unit 9, and a reflection sheet 10. The simulated sunlight irradiation device 100 emits simulated sunlight (an arrow in the figure) from the irradiation surface (upper surface) of the light guide plate 8 toward the object to be measured 21. For example, when measuring the characteristics of the measurement object 21 that is a solar cell, the measurement terminal 30a of the measurement unit 30 is connected to the measurement object 21, and the characteristics are measured. Hereinafter, the simulated solar light irradiation device 100 will be described in detail.

  In the following description, the irradiation surface side of the light guide plate 8 is the upper side, and the opposite side (back side) of the irradiation surface is the lower side. Also, the upper direction is the z direction, the direction from the left end to the right end of the light guide plate 8 in FIG. 1 is the x direction, and the back direction in FIG. 1 is the y direction.

  The light guide plate 8 is provided between the two light introducing portions 20 arranged to face each other. Pseudo sunlight is irradiated to both side surfaces of the light guide plate 8 from the two light introducing portions 20 disposed on both sides. The light guide plate 8 emits simulated sunlight from the irradiation surface (upper surface) of the light guide plate 8. The light guide plate 8 is preferably made of quartz glass or the like in order to increase the transmittance.

  The light extraction portion 9 is formed on the lower surface (back surface) of the light guide plate 8. The light extraction unit 9 extracts the artificial sunlight emitted from the light introduction unit 20 to the irradiation surface of the light guide plate 8. Specifically, light (pseudo sunlight) that has entered the light guide plate 8 from the light introduction unit 20 propagates through the light guide plate 8. At this time, the light hitting the light extraction unit 9 is emitted to the irradiation surface of the light guide plate 8. Thereby, it becomes possible to irradiate uniform pseudo-sunlight from the irradiation surface of a wider area. In addition, the light extraction part 9 can be formed, for example from a scatterer, can scatter the pseudo sunlight inside the light-guide plate 8, and can guide it to an irradiation surface. Moreover, if the pattern of the scatterer is changed, the illuminance unevenness of the simulated sunlight can be adjusted. For example, a dot-shaped pattern can be formed on the light extraction portion 9 by printing or molding.

  The reflection sheet 10 is a member that reflects light leaking downward from the light guide plate 8 or the light extraction unit 9 to the irradiation surface side of the light guide plate 8.

  The light introducing portions 20 are disposed on both side surfaces of the light guide plate 8. In the simulated sunlight irradiation device 100, the two light introduction units 20 emit simulated sunlight to both ends of the light guide plate 8. For this reason, it becomes possible to emit pseudo-sunlight with a larger amount of light (illuminance) from the irradiation surface. However, the light introduction part 20 does not need to be provided at both ends of the light guide plate 8, and may be provided only at one end of the light guide plate 8. The optical component configurations of the two light introducing sections 20 are the same.

(Configuration of light introducing unit 20)
The configuration of the light introducing unit 20 will be described with reference to FIGS. 1 and 2. FIG. 2 is a view of the light introducing portion 20 as viewed from the irradiation surface (upper surface) side of the light guide plate 8.

  The light introduction unit 20 includes a halogen light source 1 (first light source), a light collecting member 2, a light guide member 3, an optical filter (optical member) 4, a wavelength selection member 5, an optical coupling member 6, a reflection member 7, and a xenon light source 11. (Second light source), a light collecting member 12, a light guide member 13, an optical filter 14, and a reflecting member 17.

  The light introducing unit 20 generates simulated sunlight by mixing the light emitted from the halogen light source 1 and the xenon light source 11 with the wavelength selection member 5, and the simulated sunlight is applied to the end face (incident surface) of the light guide plate 8. Irradiate. Specifically, the halogen light source 1 and the xenon light source 11 are light sources provided in the simulated sunlight irradiation device 100. The halogen light source 1 and the xenon light source 11 irradiate light having a spectral distribution (spectral distribution) necessary for generating pseudo-sunlight. Light emitted from the halogen light source 1 and the xenon light source 11 has different spectral distributions. The halogen light source 1 emits a large amount of light having a long wavelength component necessary for pseudo-sunlight. On the other hand, the xenon light source 11 emits a lot of light having a short wavelength component necessary for pseudo-sunlight.

  The halogen light source 1 includes a cylindrical arc tube 1a having an axial direction in the y direction and a circular cross section in the xz plane, two electrodes 1b provided at both ends of the arc tube 1a, and an inside of the arc tube 1a. The halogen lamp includes a tungsten filament 1c that connects two electrodes 1b. The arc tube 1a is formed of heat-resistant quartz glass, aluminosilicate glass, high silicate glass, or the like. The inside of the arc tube 1a is filled with an inert gas such as nitrogen or argon and a small amount of halogen gas (such as iodine or bromine). By using the cylindrical halogen light source 1 having the bases at both ends, the light intensity and spectrum in a wider area can be made uniform. Thereby, the simulated sunlight irradiation apparatus 100 can irradiate the accurate simulated sunlight over a wider area. Therefore, it is possible to realize the pseudo-sunlight irradiation device 100 that can meet the demand for a large area (for example, 1400 mm × 1000 mm) of a solar cell in recent years.

  As shown in FIG. 1, the halogen light source 1 is surrounded by the light collecting member 2 except for the direction of emission to the light guide member 3. Thereby, of the light emitted from the halogen light source 1, the light not directed to the light guide member 3 is reflected by the light collecting member 2 and emitted toward the light guide member 3. That is, the condensing member 2 collects and emits the light emitted from each light source. The condensing member 2 is an elliptical mirror, a parabolic mirror, or the like, and aligns the radiation directivity of light emitted from each light source. As a result, the light directly emitted from the halogen light source 1 and the light reflected by the light collecting member 2 are emitted toward the light guide member 3. For example, in the case of the halogen light source 1 having a cylindrical arc tube whose axial direction is the y direction, the light irradiated in the direction different from the light guide member 3 among the light irradiated in all directions in the xz plane is The light collecting member 2 reflects the light in the direction of the light guide member 3. In this way, the light imparted with directivity by the light collecting member 2 enters the light guide member 3. Therefore, the emitted light from the halogen light source 1 is used effectively.

  The reflection member 7 reflects light that is not incident on the light guide member 3 again to the light collecting member 2 side, and makes the light incident on the light guide member 3.

  The light guide member 3 is an optical element that guides the light incident inside from the incident surface to the opposite exit surface by totally reflecting the light on the wall surface and emits the light. The incident surface of the light guide member 3 is disposed close to the halogen light source 1 and is located at the opening of the reflection member 7. In the light guide member 3, a pair of side surfaces facing each other in the y direction are inclined in a tapered shape. That is, the cross-sectional area of the light guide member 3 gradually increases from the incident surface of the light guide member 3 toward the output surface. Thereby, the light incident on the light guide member 3 from the halogen light source 1 is repeatedly reflected on the side surface of the light guide member 3 and the radiation directivity is aligned. The light guide member 3 enhances the directivity of light so that the traveling direction of light is within 30 degrees with respect to the x direction in the xy plane. As a result, the light emitted from the exit surface of the light guide member 3 has high directivity in the direction perpendicular to the exit surface (the direction of the optical axis).

  The optical filter 4 is a filter that adjusts the spectrum so that the spectrum of the light from the transmitted halogen light source 1 is close to the spectrum distribution of the reference sunlight. The optical filter 4 is disposed so as to face the emission surface of the light guide member 3 and transmits light emitted from the emission surface of the light guide member 3. The optical filter 4 is an optical multilayer film formed on a glass substrate. The optical filter 4 has a transmittance that varies depending on the wavelength, and at least partially brings the spectrum of the transmitted light close to the spectrum of the reference sunlight. The optical filter 4 is usually referred to as an air mass filter (spectrum adjustment filter).

  The xenon light source 11 is a xenon lamp in which xenon is sealed in a cylindrical arc tube.

  The condensing member 12 has the same function and configuration as the condensing member 2. The condensing member 12 condenses the light from the xenon light source 11 so that the light emitted from the xenon light source 11 enters the light guide member 13.

  The reflection member 17 reflects light that does not enter the light guide member 13 toward the light collecting member 12, and makes light reflected again by the light collecting member 12 enter the light guide member 13.

  The light guide member 13 has the same function and configuration as the light guide member 3. The light guide member 13 increases the radiation directivity of light incident from the xenon light source 11 and emits light having high directivity in the z direction to the optical filter 14.

  The optical filter 14 is a filter that adjusts the spectrum so that the spectrum of the transmitted light from the xenon light source 11 is close to the spectrum distribution of the reference sunlight. The optical filter 14 is disposed to face the emission surface of the light guide member 13 and transmits light emitted from the emission surface of the light guide member 13. The optical filter 14 is obtained by forming an optical multilayer film on a glass substrate. The optical filter 14 has a transmittance that varies depending on the wavelength, and at least partially approximates the spectrum of the transmitted light to the spectrum of the reference sunlight.

  In this way, the light from the halogen light source 1 and the light from the xenon light source 11 are incident on the wavelength selection member 5 respectively. The optical axis of light from the halogen light source 1 and the optical axis of light from the xenon light source 11 are perpendicular to each other.

  The wavelength selection member 5 is a member that reflects light on a shorter wavelength side than a predetermined boundary wavelength and transmits light on a longer wavelength side than the boundary wavelength. The plate-like wavelength selection member 5 is disposed with its incident surface inclined 45 degrees with respect to the optical axis of the light that has passed through the optical filter 4. In addition, the wavelength selection member 5 is disposed such that the incident surface is inclined 45 degrees with respect to the optical axis of the light that has passed through the optical filter 14.

  FIG. 3 is a diagram showing the transmittance for light incident on the wavelength selection member 5 at an incident angle of 45 degrees. As shown in FIG. 3, the wavelength selection member 5 has a function of wavelength selection. That is, the wavelength selection member 5 selects (extracts) light necessary for the pseudo-sunlight from the light emitted from the halogen light source 1 and the xenon light source 11, and mixes the selected light to synthesize the pseudo-sunlight. Functions as a mixing member. Specifically, the wavelength selection member 5 reflects light having a wavelength less than a predetermined wavelength (shorter wavelength side than the predetermined wavelength (650 nm in FIG. 3)), and light having a wavelength longer than the predetermined wavelength (longer wavelength side than the predetermined wavelength). Transparent. In other words, the wavelength selection member 5 has a function of reflecting light on the short wavelength side while transmitting light on the long wavelength side necessary for the pseudo-sunlight. Then, the pseudo-sunlight is synthesized by mixing the light on the long wavelength side and the light on the short wavelength side.

  More specifically, the light emitted from the halogen light source 1 includes many components on the long wavelength side necessary for the pseudo-sunlight. On the other hand, the emitted light from the xenon light source 11 includes many components on the short wavelength side necessary for the pseudo-sunlight. The wavelength selection member 5 has a boundary wavelength in the range of 600 to 800 nm, reflects light having a wavelength less than the boundary wavelength, and transmits light having a wavelength equal to or greater than the boundary wavelength. That is, only the light having a wavelength longer than the boundary wavelength (light having a longer wavelength side) out of the light emitted from the halogen light source 1 passes through the wavelength selection member 5 and enters the optical coupling member 6. On the other hand, of the light emitted from the xenon light source 11, only light having a wavelength shorter than the boundary wavelength (light having a short wavelength component) is reflected by the wavelength selection member 5 and enters the optical coupling member 6.

  For example, assume that light having a wavelength of 700 nm or more is used as the light from the halogen light source 1 and light from the xenon light source 11 is used at a wavelength of less than 700 nm. In this case, the boundary wavelength between reflection and transmission of the wavelength selection member 5 is a wavelength of 700 nm. That is, the wavelength selection member 5 has a characteristic of reflecting light having a wavelength shorter than 700 nm and transmitting light having a wavelength longer than 700 nm. Thereby, only the light of a wavelength required for pseudo sunlight is selected by the wavelength selection member 5. The selected lights are combined and emitted as simulated sunlight. In addition, what is necessary is just to set arbitrarily the boundary wavelength of the light which the wavelength selection member 5 reflects or permeate | transmits. However, in order to reduce the emission line component of the emission spectrum of the xenon light source 11, it is preferable to select in the range of 600 to 700 nm. Furthermore, a wavelength-dependent mirror or filter can be used as the wavelength selection member 5. For example, a cold mirror, a hot mirror, or the like can be used as the wavelength selection member 5.

  As described above, the wavelength selection member 5 is necessary for synthesizing the long-wavelength component light necessary for synthesizing the pseudo sunlight included in the emitted light of the halogen light source 1 and the pseudo sunlight included in the emitted light of the xenon light source 11. The pseudo-sunlight is generated by extracting light having a short wavelength component. At this time, the light of the short wavelength component of the halogen light source 1 not subjected to spectrum control is removed, and similarly, the light of the long wavelength component of the xenon light source 11 not subjected to spectrum control is removed. Therefore, it becomes possible to make the emission spectrum of pseudo sunlight more approximate to the emission spectrum of reference sunlight.

  The optical coupling member 6 is an optical element that guides the light incident inside from the incident surface to the opposite exit surface by totally reflecting the light on the wall surface and emits the light. The incident surface of the optical coupling member 6 is disposed close to the wavelength selection member 5. In the optical coupling member 6, a pair of surfaces facing each other in the z direction are inclined in a tapered shape. That is, the cross-sectional area of the optical coupling member 6 gradually decreases from the incident surface to the outgoing surface of the optical coupling member 6. Thereby, the light which spreads in the z direction and is incident on the optical coupling member 6 from the wavelength selection member 5 is emitted from the emission surface whose width in the z direction is narrower than the incident surface. The light emitted from the emission surface of the optical coupling member 6 enters the end surface of the light guide plate 8.

  The light guide plate 8 is disposed close to the optical coupling member 6 so that the end surface of the light guide plate 8 faces the emission surface of the optical coupling member 6. Since the width of the incident light in the z direction can be reduced by the optical coupling member 6, the thickness of the light guide plate 8 in the z direction can be reduced. The light guide plate 8 is preferably made of quartz glass or the like in order to increase the transmittance. Quartz glass is expensive, but if the optical coupling member 6 is used, the thickness of the light guide plate 8 can be reduced while improving the light utilization efficiency, so that the cost can be reduced.

(Principle of simulated sunlight irradiation)
Since the halogen light source 1 and the xenon light source 11 are non-directional light sources, the emitted light from each light source becomes diffused diffused light. For this reason, it is preferable to control the directivity of the emitted light from each light source so that the emitted light from each light source enters the wavelength selection member 5 at a predetermined angle. Here, as shown in FIG. 2, the light guide members 3 and 13 have a tapered shape, and a pair of opposing surfaces have a trapezoidal shape. That is, the width (cross-sectional area) of the light guide members 3 and 13 gradually increases from the entrance surface to the exit surface of the light guide members 3 and 13. With such a structure, the directivity (radiation angle) of the light emitted from the halogen light source 1 and the xenon light source 11 is improved while being reflected a plurality of times on the side surfaces of the light guide members 3 and 13. As a result, light with uniform directivity (radiation angle is controlled) is emitted from the emission surfaces of the light guide members 3 and 13. The emission angle of the light emitted from the light guide members 3 and 13 is controlled by the inclination angle of the side surfaces of the light guide members 3 and 13 and the length of the light guide members 3 and 13 in the light traveling direction.

  Accordingly, the light emitted from the halogen light source 1 and the xenon light source 11 has the same radiation directivity by the light collecting members 2 and 12. Further, the light emitted from the halogen light source 1 and the xenon light source 11 has the same radiation directivity by the light guide members 3 and 13. The light with uniform directivity is transmitted through the optical filters 4 and 14 that adjust the optical spectrum, and then enters the wavelength selection member 5.

  The advantage of aligning the directivity of light by the light guide members 3 and 13 is related to the structure of the optical filters 4 and 14. Specifically, the optical filters 4 and 14 have a structure in which a plurality of thin films are stacked. For this reason, as the incident angle to the optical filters 4 and 14 is larger with respect to the vertical incidence to the optical filters 4 and 14, the transmittance characteristic also changes. That is, when light with low directivity is incident on the optical filters 4 and 14, pseudo sunlight having a spectral distribution deviating from the spectral distribution of the reference sunlight is generated.

  However, if the light guide members 3 and 13 have the same light directivity, pseudo-sunlight close to the spectrum distribution of the reference sunlight can be generated. Specifically, the light emitted from the light guide members 3 and 13 has an incident angle range of ± 30 ° or less with respect to the vertical axis of the optical filters 4 and 14. Since the optical filters 4 and 14 are designed to obtain a predetermined transmission characteristic when the incident angle is 0 °, that is, when the light enters the optical filters 4 and 14 perpendicularly, the optical filters 4 and 14 for incident light are obtained. The vertical phase shift (approximated by 1-cos 30 °) is 14% at the maximum, and even when the incident angle extends from 0 ° to 30 °, the phase shift is an average of 0% to 14%. Value. Therefore, the change in the transmittance of the optical filters 4 and 14 with respect to the case where the incident angle is 0 ° is small.

  Thus, since highly directional light is incident on the optical filters 4 and 14, the controllability of the spectrum is improved, and pseudo-sunlight closer to the reference sunlight can be formed. As a result, the light obtained by passing through the optical filters 4 and 14 becomes closer to the actual sunlight, and as a result, the pseudo-sunlight is deviated from the reference sunlight (spectrum matching degree) within ± 5%. Japanese Industrial Standard (JIS) MS-class light.

  In addition, since the simulated solar light irradiation device 100 includes the light guide members 3 and 13, the directivity of light so that the halogen light and the xenon light are incident on the optical filters 4 and 14 and the wavelength selection member 5 at a predetermined angle. Is controlled. For this reason, the loss until the light quantity of xenon light and halogen light reaches the wavelength selection member 5 is suppressed.

  Only one of the light guide members 3 and 13 can control the directivity of halogen light or xenon light and can enter the wavelength selection member 5 at a predetermined angle. In the simulated sunlight irradiation device 100, the halogen light source 1 and the xenon light source 11 are used as light sources for obtaining simulated sunlight. However, a high-pressure discharge lamp containing a halogen gas may be used instead of the halogen light source 1, or another light source may be used instead of the xenon light source 11. Moreover, as a kind of light source, you may use a point light source etc. besides a rod-shaped light source.

(Light guide member)
Since the halogen light source 1 and the xenon light source 11 are omnidirectional light sources, not all light enters the light guide members 3 and 13. In the case where leakage light (stray light) leaking from the reflecting members 7 and 17 occurs without entering the light guide members 3 and 13, the stray light may enter the device under test 21. Such stray light is unnecessary light for measurement and affects the measurement result. In particular, when stray light that has not been spectrally adjusted by the optical filters 4 and 14 is mixed into the light emitted from the light guide plate 8, the spectrum of the light irradiated to the object to be measured 21 deviates from the spectrum of the ideal simulated sunlight. As a result, a deviation occurs in the measurement result of the characteristics of the DUT 21.

  Therefore, the thickness t of the light guide member 3 is preferably equal to or larger than the diameter of the circular section in the arc tube 1a of the halogen light source 1. Further, the thickness t of the light guide member 3 is preferably 1.5 times or more the diameter of the arc tube 1a. For example, when the diameter of the arc tube 1a is 20 mm, the thickness of the light guide member 3 is 30 mm. Thereby, most of the light from the halogen light source 1 can be incident on the light guide member 3, and the generation of stray light can be reduced.

  In order to form a thick light guide member 3 having a thickness of 30 mm or more, borosilicate crown glass (BK7), quartz glass, or the like is preferable. Of these, quartz glass is expensive, and borosilicate crown glass is advantageous in terms of cost.

  In addition, the light guide member 3 is made of a glass material (glass material) having such a length that the absorptance with respect to infrared light having a wavelength of mid-infrared (light having a wavelength of 2.5 μm to 4.0 μm) or more is 95% or more. ing. As a result, infrared light having a wavelength equal to or greater than the mid-infrared wavelength of the light emitted from the halogen light source 1 is almost completely absorbed by the light guide member 3 and emitted from the light guide plate 8 before entering the optical filter 4. It is possible to almost completely prevent the mixing of infrared rays above the mid-infrared ray into the light. In other words, the light guide member 3 can almost completely prevent radiation to the measurement object 21 from the mid-infrared ray to the infrared ray.

  Infrared rays equal to or higher than the mid-infrared contained in the light emitted from the light guide plate 8 have an action of increasing the temperature of the device under test 21 when irradiated onto the device under test 21. If the temperature of the device under test 21 is unnecessarily increased, the characteristics will change and the accuracy of the measurement result will be reduced. That is, the measurement error increases. In particular, infrared rays of mid-infrared or higher included in the halogen light source 1 in which light having a wavelength longer than a predetermined boundary wavelength is selected by the wavelength selection member 5 can cause measurement errors.

  However, in the present embodiment, the light guide member 3 is made of a glass material (glass material) that easily absorbs infrared rays having a wavelength longer than or equal to the mid-infrared wavelength. A part of the infrared rays is absorbed by the light guide member 3. As a result, it is possible to reduce the amount of infrared rays equal to or higher than the mid-infrared rays contained in the light (measurement light) emitted from the light guide plate 8. Thereby, the measurement error resulting from the temperature rise of the to-be-measured object 21 by the infrared rays more than mid-infrared can be suppressed.

  Specifically, it is preferable to use, as the light guide member 3, a glass material that has an absorption rate of 90% or more for most of infrared rays having wavelengths longer than or equal to the mid-infrared when propagating a distance of 10 mm. An example of such a glass material is borosilicate crown glass (BK7). The transmittance of borosilicate crown glass gradually decreases as the wavelength increases from near mid-infrared. In addition, borosilicate crown glass has a high absorptivity of infrared rays greater than mid-infrared rays. Even if it is the shortest mid-infrared ray (wavelength 2500 nm), the absorption rate when propagating over a distance of 10 mm is 41%. Therefore, if the length is 180 mm, 99.2% or more of light is absorbed. The

  Further, when the amount of irradiation light is very large, it may be advantageous not to transmit the infrared region as much as possible.

Then, the distance L between the incident surface 3a that is the end surface of the light guide member 3 on the halogen light source 1 side (light incident side) and the exit surface 3b that is the end surface of the optical filter 4 side (light emission side) is appropriately adjusted. Thereby, the absorption factor of the infrared rays of a predetermined wavelength in the light guide member 3 can be adjusted. That is, assuming that the absorptivity of an infrared ray having a certain wavelength when propagating a distance of 10 mm is a%, in the light guide member 3 propagating a distance of Lmm, the absorptivity of the infrared ray of the wavelength is 10) Ascend at a power ratio. In particular,
1-((100-a) / 100) ^{L / 10}
It becomes.

  For example, when a borosilicate crown glass is used as the light guide member 3, the absorption rate at 10 mm is about 3% at a wavelength of 1350 nm. Therefore, the absorption rate is about 26% at L = 100 mm, and the absorption rate is 46% at L = 200 mm. , L = 240 mm, the absorption rate is 50% or more.

  Thus, by setting the length L of the light guide member 3, it is possible to appropriately set the absorption rate of a wide range of infrared rays including infrared rays equal to or higher than the middle infrared ray in the light guide member 3. From the viewpoint of heat absorption, the length L of the light guide member is preferably such that the absorptance with respect to infrared rays having wavelengths longer than mid-infrared is 95% or more. More preferably, the length is such that the absorptance with respect to infrared rays having wavelengths longer than mid-infrared is 99% or more. Further, when the width of the incident surface 3a which is the end surface of the light guide member 3 on the halogen light source 1 side (light incident side) is w, it is preferable that L ≧ 6w. Thereby, the absorption factor of the infrared rays more than the middle infrared rays in the light guide member 3 can be increased, and the amount of the infrared rays more than the middle infrared rays incident on the object to be measured 21 can be further reduced.

(Other)
In the above description, the reflection member 7 is provided in order to suppress stray light not incident on the light guide member 3, but the shape of the reflection member 7 is not limited to that shown in FIGS. For example, as shown in FIG. 4, a lamp cover 27 having an opening for emitting light from the halogen light source 1 to the light guide member 3 may be provided as a member for suppressing stray light. The lamp cover 27 surrounds the halogen light source 1 and the light collecting member 2. Here, the lamp cover 27 covers up to the electrode 1b of the halogen light source 1 for connecting a lead wire (not shown).

  Below, the Example of the simulated sunlight irradiation apparatus 100 of Embodiment 1 is demonstrated.

  FIG. 5 is a perspective view showing the configuration of the simulated solar light irradiation apparatus 100 of the present embodiment. In order to make the relationship between the constituent members easy to understand, in FIG. 5, some members are shown as being translucent, and an external housing, a support, and the like are omitted.

  In FIG. 5, the position at which the DUT 21 that is a solar cell is arranged is indicated by a dotted line. The irradiation area of the DUT 21 that can be arranged is about 1400 mm × 1000 mm at the maximum. The DUT 21 is arranged above the light guide plate 8.

  On both sides of the light guide plate 8, light introducing portions 20 are respectively installed. In one light introducing portion 20, 16 halogen light sources 1 are arranged along the y direction. The plurality of condensing members 2 are installed so as to surround the filament 1 c corresponding to each halogen light source 1. The plurality of light guide members 3 are installed so that the incident surfaces thereof face the halogen light sources 1 corresponding to the halogen light sources 1.

  Since the halogen light source 1 is difficult to manufacture as long as one side of the solar cell due to its characteristics, a plurality of halogen light sources 1 having a filament length of about 40 mm are used side by side.

  A xenon light source 11 is disposed below the wavelength selection member 5. The condensing member 12 is installed so as to surround the xenon light source 11. A reflection member 17 having a plurality of openings is installed above the xenon light source 11. Eight light guide members 13 are installed corresponding to the plurality of openings of the reflection member 17.

  The light from the halogen light source 1 and the light from the xenon light source 11 are respectively emitted from the light guide members 3 and 13, and then passed through optical filters (not shown) corresponding to the light components to adjust the spectrum. Thereafter, the light from the halogen light source 1 and the light from the xenon light source 11 are combined with light in a wavelength range selected by transmission or reflection by the wavelength selection member 5, and enter the optical coupling member 6 as pseudo-sunlight. The artificial sunlight emitted from the optical coupling member 6 enters the light guide plate 8. The artificial sunlight that has entered the light guide plate 8 is emitted above the light guide plate 8 by the light extraction unit 9 or the reflection sheet 10 and is irradiated on the object to be measured 21.

  Here, the light guide member 3 is made of borosilicate crown glass, which is a glass material having an absorptivity with respect to infrared rays having wavelengths longer than the mid-infrared ray. As a result, a part of the infrared light above the middle infrared ray out of the light emitted from the halogen light source 1 is absorbed by the light guide member 3, and the amount of the infrared light above the middle infrared ray irradiated to the object to be measured 21 can be reduced. it can.

  Hereinafter, another embodiment of the simulated solar light irradiation apparatus will be described.

  FIG. 6 is a diagram showing a schematic configuration of the halogen light source 51 of the present embodiment. The halogen light source 51 is provided between an elongated cylindrical arc tube 51a, a lead wire connecting portion 51b for connecting lead wires provided at both ends of the arc tube 51a, and a lead wire connecting portion 51b at both ends. Two filaments 51c are provided. An inert gas and a trace amount of halogen gas are sealed inside the arc tube 51a. The two filaments 51c are connected in series between the electrodes of the two lead wire connection portions 51b. Since each filament 51c functions as a light emitting part, the halogen light source 51 has two light emitting parts. The lead wire 51d connected to each lead wire connecting portion 51b is connected to a control circuit portion including a power source. The length of the halogen light source 51 (distance between both ends) is 215 mm, and the length of each filament 51c is 40 mm. The arc tube 51a has a diameter of 20 mm.

  Each filament 51 c of the halogen light source 51 is disposed at a position corresponding to the incident surface of the light guide member 3. Since the halogen light source 51 includes two filaments 51c, the number of the halogen light sources 51 can be reduced. That is, the installation of the halogen light source 51 in the simulated solar light irradiation device, the installation (removal and routing) of each lead wire 51d, the connection of the lead wire 51d to a control circuit unit (not shown), and the like are facilitated.

  In order to supply light of illuminance at the sunlight level to a large-area solar cell, each halogen light source 51 is also required to have a large output. Therefore, it is necessary that the arc tube 51a has a diameter of about 10 mm to 30 mm (in FIG. 7, the diameter is 20 mm).

  If the size of the arc tube 51a (and thus the filament) is increased, the required height in the z direction of the incident surface of the light guide member 3 is increased even if the light is collected by the light collecting member. Therefore, the thickness of the glass material required as the light guide member 3 in the present embodiment is much larger than the thickness of the normal glass material. Examples of materials that can be supplied as a thick glass material include quartz glass and BK7.

  FIG. 7 is a perspective view showing a detailed configuration of the light irradiation device 50 of the present embodiment. FIG. 8 is a perspective view showing a detailed configuration of the light irradiation device 50 of the present embodiment viewed from another angle. 7 is a view of the light irradiation device 50 as viewed from the side where the light guide member 3 is located, and FIG. 8 is a view of the light irradiation device 50 as viewed from the lamp cover 57 side.

  The light irradiation device 50 includes a light collecting member 52, a light collecting member cover 52a, and a lamp cover 57 in addition to the halogen light source 51 described with reference to FIG. Further, the light irradiation device 50 includes a side reflecting mirror 52 c and a frame body 58. The condensing member 52 is an elliptical reflecting mirror, and side reflecting mirrors 52 c for allowing light from the halogen light source 51 to enter the light guide member 3 are disposed on both side surfaces of the condensing member 52. The light collecting member cover 52 a covers the back surface of the light collecting member 52. A position corresponding to the filament 51c of the halogen light source 51 is covered with a light collecting member 52 and a light collecting member cover 52a.

  The light collecting member 52 is attached to the light collecting member cover 52a. The condensing member cover 52 a is attached to the frame body 58. Further, the halogen light source 51 is inserted into the hole 52b of the light collecting member cover 52a and fixed to the frame body 58. The lamp cover 57 covers the portion of the halogen light source 51 that does not correspond to the filament 51c and the end portion close to the lead wire connecting portion 51b so as to cover the rear side of the halogen light source 51 (the side opposite to the position of the light guide member). ) To the light collecting member cover 52a. As described above, the lamp cover 57 covers a portion of the halogen light source 51 that is not covered by the light condensing member cover 52a.

  The halogen light source 51 is incorporated into the simulated solar light irradiation device by attaching the frame 58 (that is, the light irradiation device 50) to which the halogen light source 51, the condensing member 52, the lamp cover 57, and the like are attached to the simulated solar light irradiation device. be able to.

  FIG. 9 is a perspective view showing a partial configuration around the halogen light source 51 in the pseudo-sunlight irradiation apparatus of the present embodiment. The light guide member 3 is disposed at a position corresponding to each filament 51c.

  In this embodiment, the thickness t of the light guide member 3 is equal to or larger than the diameter of the arc tube 51a of the halogen light source 51, specifically, 1.5 times 30 mm. Thereby, most of the light emitted from the halogen light source 51 can be made incident on the light guide member 3, and the amount of stray light can be suppressed.

  The width w of the light incident surface of the light guide member 3 is equal to the length 40 mm of the filament 51 c of the halogen light source 1. The distance L between the light incident surface and the light exit surface of the light guide member 3 is longer than 240 mm (6 times w) compared to the width w (= 40 mm) of the incident surface. Further, the light guide member 3 is made of borosilicate crown glass, which is a glass material having absorptivity with respect to infrared rays having wavelengths longer than the mid-infrared ray. As described above, in the case of propagating a distance of 10 mm in the borosilicate crown glass, the infrared absorption rate of the middle infrared ray or higher is 90% or higher (transmittance lower than 10%). Therefore, in the light guide member 3 with L = 240 mm, the absorption rate of infrared rays equal to or higher than the middle infrared ray is almost 100%.

  Thereby, the amount of infrared rays equal to or higher than the mid-infrared ray irradiated on the device under test 21 can be further reduced. As a result, the temperature rise of the device under test 21 can be suppressed and the measurement accuracy can be improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in the embodiments are also included. It is included in the technical scope of the present invention.

  The present invention can be used for a simulated solar light irradiation apparatus.

1,51 Halogen light source (first light source)
DESCRIPTION OF SYMBOLS 1a, 51a Light emission tube 3 Light guide member 3a Incident surface 3b Output surface 4 Optical filter (optical member)
5 Wavelength selection member (mixing member)
6 Optical coupling member (mixing member)
8 Light guide plate 11 Xenon light source (second light source)
20 light introduction part 21 to-be-measured object 100 simulated sunlight irradiation apparatus

Claims (8)

A first light source and a second light source;
A mixing member that mixes light having a longer wavelength than the predetermined wavelength among the light from the first light source and light having a shorter wavelength than the predetermined wavelength among the light from the second light source;
A pseudo-sunlight irradiation device that irradiates light mixed by the mixing member as pseudo-sunlight,
A pseudo-sunlight irradiating device comprising a light guide member having a length with which an absorptance with respect to an infrared ray having a wavelength equal to or greater than a middle infrared ray is 95% or more between the first light source and the mixing member.   The simulated light irradiation apparatus according to claim 1, wherein the light guide member is borosilicate crown glass.   The said 1st light source is a halogen lamp, The simulated sunlight irradiation apparatus of Claim 1 or 2 characterized by the above-mentioned.   In the light guide member, a distance between an incident surface on which light from the first light source is incident and an output surface on which light is emitted to the mixing member is 6 times or more the width of the incident surface. The pseudo-sunlight irradiation device according to any one of claims 1 to 3. The first light source has an arc tube,
5. The simulated solar light irradiation apparatus according to claim 1, wherein a thickness of the light guide member is equal to or greater than a diameter of the arc tube.   The simulated sunlight irradiation apparatus according to claim 5, wherein the thickness of the light guide member is 1.5 times or more the diameter of the arc tube. A light source;
A light guide plate that irradiates the object to be measured with simulated sunlight using light from the light source;
A pseudo-sunlight irradiation device comprising a light guide member for guiding light emitted from the light source toward the light guide plate;
The light guide member has a function of absorbing a part of an infrared component having a wavelength equal to or greater than the mid-infrared wavelength in order to reduce an amount of incident infrared rays having a wavelength equal to or greater than the mid-infrared wavelength to the object to be measured. Simulated sunlight irradiation device. A light source;
An optical member for adjusting a spectrum of light from the light source;
A light guide plate that emits simulated sunlight using light adjusted by the optical member;
A pseudo-sunlight irradiating device comprising a light guide member for causing light emitted from the light source to enter the optical member,
The pseudo-light irradiation device, wherein the light guide member absorbs part of an infrared component having a wavelength equal to or greater than a mid-infrared wavelength in the light emitted from the light source before entering the optical member.

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