1、Designation: E 1021 06Standard Test Method forSpectral Responsivity Measurements of PhotovoltaicDevices1This standard is issued under the fixed designation E 1021; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is to be used to determine either theabsolute or relative spectral responsivity response of a single-juncti
3、on photovoltaic device. This test method requires the useof a bias light.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine
4、the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 772 Terminology Relating to Solar Energy ConversionE 927 Specification for Solar Simulation for Phot
5、ovoltaicTestingE 948 Test Method for Electrical Performance of Photovol-taic Cells Using Reference Cells Under Simulated SunlightE 973 Test Method for Determination of the Spectral Mis-match Parameter Between a Photovoltaic Device and aPhotovoltaic Reference CellE 1036 Test Methods for Electrical Pe
6、rformance of Non-concentrator Terrestrial Photovoltaic Modules and ArraysUsing Reference CellsE 1125 Test Method for Calibration of Primary Non-Concentrator Terrestrial Photovoltaic Reference Cells Us-ing a Tabular SpectrumE 1328 Terminology Relating to Photovoltaic Solar EnergyConversionE 1362 Test
7、 Method for Calibration of Non-ConcentratorPhotovoltaic Secondary Reference CellsE 2236 Test Methods for Measurement of Electrical Perfor-mance and Spectral Response of Nonconcentrator Multi-junction Photovoltaic Cells and ModulesG 173 Tables for Reference Solar Spectral Irradiances:Direct Normal an
8、d Hemispherical on 37 Tilted Surface3. Terminology3.1 DefinitionsDefinitions of terms used in this testmethod may be found in Terminology E 772 and in Terminol-ogy E 1328.3.2 Definitions of Terms Specific to This Standard:3.2.1 chopper, na rotating blade or other device used tomodulate a light sourc
9、e.3.2.2 device under test (DUT), na photovoltaic devicethat is subjected to a spectral responsivity measurement.3.2.3 irradiance mode calibration, na calibration methodin which the reference photodetector measures the irradianceproduced by the monochromatic beam.3.2.4 monitor photodetector, na photo
10、detector incorpo-rated into the optical system to monitor the amount of lightreaching the device under test, enabling adjustments to bemade to accommodate varying light intensity.3.2.5 monochromatic beam, nchopped light from a mono-chromatic source reaching the reference photodetector ordevice under
11、 test.3.2.6 monochromator, nan optical device that allows aselected wavelength of light to pass while blocking otherwavelengths.3.2.7 power mode calibration, na calibration method inwhich the reference photodetector measures the power in themonochromatic beam.3.2.8 quantum effciency, nnumber of coll
12、ected electronsper incident photon at a specific wavelength in percent units.3.2.9 reference photodetector, na photodetector used toquantify the amount of light in monochromatic beam.3.2.10 spectral bandwidth, nthe range of wavelengths in amonochromatic light source, determined as the differencebetw
13、een its half-maximum-intensity wavelengths.3.3 Symbols:1This test method is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal and OtherAlternative Energy Sources and is the direct responsibility ofSubcommittee E44.09 on Photovoltaic Electric Power Conversion.Current edition approved N
14、ov. 1, 2006. Published January 2007. Originallyapproved in 1993. Last previous edition approved in 2001 as E 1021 95 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3.1 The following symbols and units are used in this testmethod.Ailluminated device area, m2,cspeed of light in vacuum,
16、ms1,CVMimonitor photodetector calibration value for irradi-ance mode, Am2W1,CVMpmonitor photodetector calibration value for powermode, AW1esmall wavelength interval, nm or m,Eo reference total irradiance, Wm2,Eo(l)reference spectral irradiance, Wm2nm1orWm2m1,EMmonochromatic source irradiance, Wm2,Er
17、rfractional error in measurement, dimensionless,hPlancks constant, Js,Icurrent, A,Imcmonitor photodetector current during calibration, A,lmtmonitor photodetector current during test, A,Iscsolar cell short-circuit current, A,IoIscunder Eo(l), A,Jscsolar cell short-circuit current density, Am2,Kirelat
18、ive-to-absolute spectral responsivity conversionconstant for irradiance mode, Am2W1,Kprelative-to-absolute spectral responsivity conversionconstant for power mode, AW1,lwavelength, nm or m,loa specific wavelength, nm or m,Mspectral mismatch parameter,Pmonochromatic beam power reaching the photodetec
19、tor,W,fpower of the monochromatic beam or irradiance of themonochromatic beam, W or Wm2,qelementary charge, C,Qexternal quantum efficiency,Riaabsolute spectral responsivity for irradiance mode,Am2W1,Rpaabsolute spectral responsivity for power mode,AW1,Rirrelative spectral responsivity for irradiance
20、 mode, di-mensionless,Rprrelative spectral responsivity for power mode, dimen-sionless,SRspectral responsivity, AW1or Am2W1.3.3.2 Symbolic quantities that are functions of wavelengthappear as X (l).4. Summary of Test Methods4.1 The spectral responsivity of a photovoltaic device,defined as the output
21、 current per input irradiance or radiantpower at a given wavelength, and normally reported over thewavelength range to which the device responds, is determinedby the following procedure:4.1.1 A monochromatic, chopped beam of light is directedat normal incidence onto the cell. Simultaneously, a conti
22、nuouswhite light beam (bias light) is used to illuminate the DUT atirradiance levels between one third and one half of normal enduse operating conditions intended for the device. See Fig. 1.4.1.2 The magnitude of the ac (chopped) component of thecurrent at the intended voltage is monitored as the wa
23、velengthof the incident light is varied over the spectral response rangeof the device.4.2 Measurement of the absolute spectral responsivity of adevice requires knowledge of the absolute beam power orirradiance produced by the monochromatic beam. The totalpower or irradiance of the monochromatic beam
24、 incident onthe device is determined by the reference photodetector (see6.1). The absolute spectral responsivity of the device can thenbe computed using the measured device photocurrent and thepower or irradiance of the monochromatic beam.4.3 The choice of power versus irradiance mode maydepend on t
25、he spatial non-uniformity of the test device. Overallspectral response of a test device with substantial spatialnon-uniformity of response should be performed in irradiancemode.4.4 The test procedure can be adapted to provide absolute orrelative spectral responsivity measurements, depending on theca
26、libration device used, its calibration mode and the relativesizes of the calibration device, the monochromatic beam size,and the device being measured.5. Significance and Use5.1 The spectral responsivity of a photovoltaic device isnecessary for computing spectral mismatch parameter (see TestMethod E
27、 973). Spectral mismatch is used in Test MethodE 948 to measure the performance of photovoltaic cells inFIG. 1 Example of Spatial Placement of Optical Components for Spectral Responsivity MeasurementE1021062simulated sunlight, in Test Methods E 1036 to measure theperformance of photovoltaic modules
28、and arrays, in TestMethod E 1125 to calibrate photovoltaic primary referencecells using a tabular spectrum, and in Test Method E 1362 tocalibrate photovoltaic secondary reference cells. The spectralmismatch parameter can be computed using absolute or rela-tive spectral responsivity data.5.2 This tes
29、t method measures the differential spectralresponsivity of a photovoltaic device. The procedure requiresthe use of white-light bias to enable the user to evaluate thedependence of the differential spectral responsivity on theintensity of light reaching the device. When such dependenceexists, the ove
30、rall spectral responsivity should be equivalent tothe differential spectral responsivity at a light bias levelsomewhere between zero and the intended operating conditionsof the device.5.3 The spectral responsivity of a photovoltaic device isuseful for understanding device performance and materialcha
31、racteristics.5.4 The procedure described herein is appropriate for use ineither research and development applications or in productquality control by manufacturers.5.5 The reference photodetectors calibration must be trace-able to SI units through a National Institute of Standards andTechnology (NIS
32、T) spectral responsivity scale or other rel-evant radiometric scale.3,4The calibration mode of the photo-detector (irradiance or power) will affect the procedures usedand the kinds of measurements that can be performed.5.6 This test method does not address issues of samplestability.5.7 Using results
33、 obtained by this test method and additionalmeasurements, one can compute the internal quantum effi-ciency of a device.5.8 This test method is intended for use with a single-junction photovoltaic cell. It can also be used to measure thespectral responsivity of a single junction within a series-conne
34、cted, multiple-junction photovoltaic device if electricalcontact can be made to the individual junction(s) of interest.5.9 With additional procedures (see Test Methods E 2236),one can determine the spectral responsivity of individualjunctions within series-connected, multiple-junction, photovol-taic
35、 devices when electrical contact can only be made to theentire devices two terminals.5.10 Using forward biasing techniques5, it is possible toextend the procedure in this test method to measure the spectralresponsivity of individual series-connected cells within photo-voltaic modules. These techniqu
36、es are beyond the scope of thistest method.6. Apparatus6.1 Reference Photodetector:6.1.1 The following detectors are acceptable for use in thecalibration of the monochromatic light source:6.1.1.1 Pyroelectric radiometer, and6.1.1.2 Cryogenic radiometer, and6.1.1.3 Spectrally calibrated photodiode, p
37、hotodiode irradi-ance detector, or solar cell, calibrated in power or irradiancemode.NOTE 1A spectrally calibrated photodiode should have calibrationdata that includes the entire spectral response range of the device to betested. If a part of the range is omitted, it will limit the spectral range of
38、the results of this test, causing an error in computing the spectral mismatchparameter.NOTE 2Aphotodetector calibrated in power mode must have spatiallyuniform spectral responsivity over its photosensitive region. A photode-tector calibrated in irradiance mode may have spatially non-uniformspectral
39、responsivity characteristics, and must only be used with a uniform3Larason, T. C., Bruce, S. S., and Parr, A. C., NIST Special Publication 250-41Spectroradiometric Detector Measurements, Washington, DC, U.S. GovernmentPrinting Office, 1998. Also available at http:/ois.nist.gov/sdm/4Eppeldauer, G., R
40、acz, M., and Larason, T., “Optical characterization ofdiffuser-input standard irradiance meters,” SPIE Vol 3573, 1998, pp. 220-224.5Emery, K. A., “Measurement and Characterization of Solar Cells and Mod-ules,” Handbook of Photovoltaic Science and Engineering, Chapter 16, pp. 701-747,Luque, A., and H
41、egedus, S., Eds., John Wiley errors at specific wavelengths can be substantiallyhigher):95 % repeatability limit (within laboratory) 0.3 %95 % reproducibility limit (between laboratory) 1.7 %11.2 BiasThe contribution of bias to the total error willdepend upon the bias of each individual parameter us
42、ed for thedetermination of the spectral responsivity. The proceduresprescribed in these test methods are designed to reduce biaserrors as much as is reasonably possible.11.2.1 For relative spectral responsivity measurements,wavelength-independent bias errors cancel because of thenormalization perfor
43、med. However, bias errors which varywith wavelength (such as errors due to non-flat detectorresponsivity) will still introduce error into the final results.11.2.2 For absolute spectral responsivity measurements,bias errors do not cancel out from normalization and thereforepropagate directly into the
44、 final results. Of all possible sourcesof bias, two will most likely dominate the total error: photo-detector calibration and the area measurements. Errors due tomultiple reflections between apertures and detector surfacescan also occur when irradiance responsivity and power respon-sivity are conver
45、ted to each other. Waveform-related errors canalso occur when the modulated current measurement instru-mentation is calibrated for square wave or sinusoidal signalsand the measurement system produces trapezoidal waveforms(see 10.5).12. Measurement Uncertainty12.1 Measurement uncertainty is an estima
46、te of the magni-tude of systematic and random measurement errors that may bereported along with the measurement errors and the measure-ment results. An uncertainty statement relates to a particularresult obtained in a laboratory carrying out this test method, asopposed to precision and bias statemen
47、ts which are mandatoryparts of the method itself and normally derived from aninterlaboratory study conducted during development of the testmethod.12.2 It is neither appropriate for, nor the responsibility of,this test method to provide explicit values that a user of the testmethod would quote as the
48、ir estimate of uncertainty. Uncer-tainty values must be based on data generated by a laboratoryreporting results using the test method.12.3 Measurement uncertainties should be evaluated andexpressed according to the NIST guidelines8and the ISOguide9.12.4 Sources for uncertainty in spectral responsiv
49、ity mea-surements can be divided into three broad categories: photo-current measurements, radiant power measurements, and qual-ity of the monochromatic light. Appendix X1 provides a list ofpotential sources of uncertainty.12.5 Uncertainty in the measurement results obtained usingthis test method depend on the calibration uncertainties of theinstruments used and the signal noise encountered during thetest.12.6 One can gather information describing the randomuncertainty of a measurement result b
