1、Designation: E1021 12E1021 15Standard Test Method forSpectral Responsivity Measurements of PhotovoltaicDevices1This standard is issued under the fixed designation E1021; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is to be used to determine either the absolute or relative spectral responsivity response of a single-
3、junctionphotovoltaic device.1.2 Because quantum efficiency is directly related to spectral responsivity, this test method may be used to determine thequantum efficiency of a single-junction photovoltaic device (see 10.10).1.3 This test method requires the use of a bias light.1.4 The values stated in
4、 SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and he
5、alth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE772 Terminology of Solar Energy ConversionE927 Specification for Solar Sim
6、ulation for Photovoltaic TestingE948 Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated SunlightE973 Test Method for Determination of the Spectral Mismatch Parameter Between a Photovoltaic Device and a PhotovoltaicReference CellE1036 Test Methods for E
7、lectrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays UsingReference CellsE1125 Test Method for Calibration of Primary Non-Concentrator Terrestrial Photovoltaic Reference Cells Using a TabularSpectrumE1362 Test Method for Calibration of Non-Concentrator Photovoltaic Se
8、condary Reference CellsE2236 Test Methods for Measurement of Electrical Performance and Spectral Response of Nonconcentrator MultijunctionPhotovoltaic Cells and ModulesG173 Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37 Tilted Surface3. Terminology3.1 Definiti
9、onsDefinitions of terms used in this test method may be found in Terminology E772.3.2 Definitions of Terms Specific to This Standard:3.2.1 chopper, na rotating blade or other device used to modulate a light source.3.2.2 device under test (DUT), na photovoltaic device that is subjected to a spectral
10、responsivity measurement.3.2.3 irradiance mode calibration, na calibration method in which the reference photodetector measures the irradianceproduced by the monochromatic beam.1 This test method is under the jurisdiction of ASTM Committee E44 on Solar, Geothermal and Other Alternative Energy Source
11、s and is the direct responsibility ofSubcommittee E44.09 on Photovoltaic Electric Power Conversion.Current edition approved March 1, 2012Feb. 1, 2015. Published April 2012April 2015. Originally approved in 1993. Last previous edition approved in 20062012 asE1021 06.E1021 12. DOI: 10.1520/E1021-12.10
12、.1520/E1021-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is i
13、ntended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the cu
14、rrent versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.4 monitor photodetector, na photodetector incorporated into the optical system to monitor
15、the amount of light reachingthe device under test, enabling adjustments to be made to accommodate varying light intensity.3.2.5 monochromatic beam, nchopped light from a monochromatic source reaching the reference photodetector or deviceunder test.3.2.6 monochromator, nan optical device that allows
16、a selected wavelength of light to pass while blocking other wavelengths.3.2.7 power mode calibration, na calibration method in which the reference photodetector measures the power in themonochromatic beam.3.2.8 reference photodetector, na photodetector calibrated photodetector with a known spectral
17、responsivity over awavelength range and used to quantify the amount of light in a monochromatic beam.3.2.9 spectral bandwidth, nthe range of wavelengths in a monochromatic light source, determined as the difference betweenits half-maximum-intensity wavelengths.3.3 Symbols:3.3.1 The following symbols
18、 and units are used in this test method.Ailluminated device area, m2,cspeed of light in vacuum, 299792458 ms1,CVMimonitor photodetector calibration value for irradiance mode, Am2W1,CVMpmonitor photodetector calibration value for power mode, AW1small wavelength interval, nm or m,Eo reference total ir
19、radiance, Wm2,Eo()reference spectral irradiance, Wm2nm1 or Wm2m1,EMmonochromatic source irradiance, Wm2,Errfractional error in measurement, dimensionless,hPlancks constant, 6.626069571034Js,Icurrent, A,Imcmonitor photodetector current during calibration, A,lmtmonitor photodetector current during tes
20、t, A,Iscsolar cell short-circuit current, A,IoIsc under Eo(), A,Jscsolar cell short-circuit current density, Am2,Kirelative-to-absolute spectral responsivity conversion constant for irradiance mode, Am2W 1,Kprelative-to-absolute spectral responsivity conversion constant for power mode, AW1,wavelengt
21、h, nm or m,oa specific wavelength, nm or m,Mspectral mismatch parameter,Pmonochromatic beam power reaching the photodetector, W,power of the monochromatic beam or irradiance of the monochromatic beam, W or Wm2,qelementary charge, 1.6021765651019 C,Qexternal quantum efficiency dimensionless or percen
22、t,Riaabsolute spectral responsivity for irradiance mode, Am2W1,Rpaabsolute spectral responsivity for power mode, AW1,Rirrelative spectral responsivity for irradiance mode, dimensionless,Rprrelative spectral responsivity for power mode, dimensionless,SRspectral responsivity, AW1 or Am2W1.3.3.2 Symbol
23、ic quantities that are functions of wavelength appear as X().4. Summary of Test Method4.1 The spectral responsivity of a photovoltaic device, defined as the output current per input irradiance or radiant power at agiven wavelength, and normally reported over the wavelength range to which the device
24、responds, is determined by the followingprocedure:4.1.1 A monochromatic, chopped or pulsed beam of light is directed at normal incidence onto the cell. Simultaneously, acontinuous white light beam (bias light) is used to illuminate the DUT at irradiance levels between one third and one half of norma
25、lintended for end use operating conditions intended for of the device. See Fig. 1.4.1.2 The magnitude of the ac (chopped) component of the current at the intended voltage is monitored as the wavelength ofthe incident light is varied over the spectral response range of the device.4.2 Measurement of t
26、he absolute spectral responsivity of a device requires knowledge of the absolute beam power or irradianceproduced by the monochromatic beam. The total power or irradiance of the monochromatic beam incident on the device isE1021 152determined by the reference photodetector (see 6.1). The absolute spe
27、ctral responsivity of the device can then be computed usingthe measured device photocurrent and the power or irradiance of the monochromatic beam.4.3 The choice of power versus irradiance mode may depend on the spatial non-uniformity of the test device. device or theincident monochromatic beam. Over
28、all spectral response of a test device with substantial spatial non-uniformity of response shouldbe performed in irradiance mode.mode with a monochromatic beam of high spatial uniformity.4.4 The test procedure can be adapted to provide absolute or relative spectral responsivity measurements, dependi
29、ng on thecalibration device used, its calibration mode and the relative sizes of the calibration device, the monochromatic beam size, and thedevice being measured.5. Significance and Use5.1 The spectral responsivity of a photovoltaic device is necessary for computing spectral mismatch parameter (see
30、 Test MethodE973). Spectral mismatch is used in Test Method E948 to measure the performance of photovoltaic cells in simulated sunlight, inTest Methods E1036 to measure the performance of photovoltaic modules and arrays, in Test Method E1125 to calibratephotovoltaic primary reference cells using a t
31、abular spectrum, and in Test Method E1362 to calibrate photovoltaic secondaryreference cells. The spectral mismatch parameter can be computed using absolute or relative spectral responsivity data.5.2 This test method measures the differential spectral responsivity of a photovoltaic device. The proce
32、dure requires the use ofwhite-light bias to enable the user to evaluate the dependence of the differential spectral responsivity on the intensity of lightreaching the device. When such dependence exists, the overall spectral responsivity should be equivalent to the differential spectralresponsivity
33、at a light bias level somewhere between zero and the intended operating conditions of the device. Depending on thelinearity response of the DUT over the intensity range up to the intended operating conditions, it may not be necessary to set upa very high light bias level.5.3 The spectral responsivit
34、y of a photovoltaic device is useful for understanding device performance and materialcharacteristics.5.4 The procedure described herein is appropriate for use in either research and development applications or in product qualitycontrol by manufacturers.5.5 The reference photodetectors calibration m
35、ust be traceable to SI units through a National Institute of Standards andTechnology (NIST) spectral responsivity scale or other relevant radiometric scale.3,4 The calibration mode of the photodetector(irradiance or power) will affect the procedures used and the kinds of measurements that can be per
36、formed.5.6 This test method does not address issues of sample stability.5.7 Using results obtained by this test method and additional measurements including reflectance versus wavelength, one cancompute the internal quantum efficiency of a device. These measurements are beyond the scope of this test
37、 method.5.8 This test method is intended for use with a single-junction photovoltaic cell. It can also be used to measure the spectralresponsivity of a single junction within a series-connected, multiple-junction photovoltaic device if electrical contact can be madeto the individual junction(s) of i
38、nterest.3 Larason, T. C., Bruce, S. S., and Parr, A. C., NIST Special Publication 250-41 Spectroradiometric Detector Measurements, Washington, DC, U.S. Government PrintingOffice, 1998. Also available at http:/ois.nist.gov/sdm/4 Eppeldauer, G., Racz, M., and Larason, T., “Optical characterization of
39、diffuser-input standard irradiance meters,” SPIE Vol 3573, 1998, pp. 220-224.FIG. 1 Example of Spatial Placement of Optical Components for Spectral Responsivity MeasurementE1021 1535.9 With additional procedures (see Test Methods E2236), one can determine the spectral responsivity of individual junc
40、tionswithin series-connected, multiple-junction, photovoltaic devices when electrical contact can only be made to the entire devicestwo terminals.5.10 Using forward biasing techniques5, it is possible to extend the procedure in this test method to measure the spectralresponsivity of individual serie
41、s-connected cells within photovoltaic modules. These techniques are beyond the scope of this testmethod.6. Apparatus6.1 Reference Photodetector:6.1.1 The following detectors are acceptable for use in the calibration of the monochromatic light source:6.1.1.1 Pyroelectric radiometer, and6.1.1.2 Cryoge
42、nic radiometer, and6.1.1.3 Spectrally calibrated photodiode, photodiode irradiance detector, or solar cell, calibrated in power or irradiance mode.NOTE 1A spectrally calibrated photodiode should have calibration data that includes the entire spectral response range of the device to be tested. Ifa pa
43、rt of the range is omitted, it will limit the spectral range of the results of this test, causing an error in computing the spectral mismatch parameter.NOTE 2A photodetector calibrated in power mode must have spatially uniform spectral responsivity over its photosensitive region. A photodetectorcali
44、brated in irradiance mode may have spatially non-uniform spectral responsivity characteristics, and must only be used with a uniform monochromaticbeam larger than its surface area. See also Table 1.6.1.2 The reference photodetector must have a known linear current versus incident light intensity rat
45、io over the range ofintensities and wavelengths of the monochromatic light source.6.1.3 The reference photodetectors calibration must be traceable to SI units through a National Institute of Standards andTechnology (NIST) spectral responsivity scale or other relevant radiometric scale.3,46.1.4 The u
46、niformity of responsivity over the surface of the reference photodetector must be characterized if it will not beentirely illuminated (overfill illumination) by the monochromatic light beam. A photodetector with spatially uniform sensitivity issuitable for use in power mode. both power mode and irra
47、diance mode measurements. Non-uniform detectors are suitable for usein irradiance mode with uniform light beams only. The non-uniformity of the incident radiation should be ideally better than 62%. For best results, use a photodetector with the best spatial response uniformity available. The spatial
48、 uniformity map of thereference detector are typically provided as part of the calibration documents for one or two wavelengths.6.1.5 The reference photodetectors angular sensitivity must be compatible with the beam divergence angle of themonochromatic light source in 6.3.6.1.6 The reference photode
49、tectors frequency response must be known or invariant in the range of chopping frequencies to beused in the test.6.1.7 If the reference photodetector has an aperture smaller than its photosensitive area, then irradiance and power modecalibrations can be converted to each other. If calibrated in irradiance mode, the aperture must have limited the monochromaticbeam to the photosensitive region during the photodetectors calibration. If calibrated in power mode, the aperture mu
