340:, where the QE value is fairly constant across the entire spectrum of wavelengths measured. However, the QE for most solar cells is reduced because of the effects of recombination, where charge carriers are not able to move into an external circuit. The same mechanisms that affect the collection probability also affect the QE. For example, modifying the front surface can affect carriers generated near the surface. Highly doped front surface layers can also cause 'free carrier absorption' which reduces QE in the longer wavelengths. And because high-energy (blue) light is absorbed very close to the surface, considerable recombination at the front surface will affect the "blue" portion of the QE. Similarly, lower energy (green) light is absorbed in the bulk of a solar cell, and a low diffusion length will affect the collection probability from the solar cell bulk, reducing the QE in the green portion of the spectrum. Generally, solar cells on the market today do not produce much electricity from
27:
122:
277:
539:
366:
Conventional measurement of the EQE will give the efficiency of the overall device. However it is often useful to have a map of the EQE over large area of the device. This mapping provides an efficient way to visualize the homogeneity and/or the defects in the sample. It was realized by researchers
194:
332:
of light and the collection of charges. Once a photon has been absorbed and has generated an electron-hole pair, these charges must be separated and collected at the junction. A "good" material avoids charge recombination. Charge recombination causes a drop in the external quantum efficiency.
190:
The IQE is always larger than the EQE in the visible spectrum. A low IQE indicates that the active layer of the solar cell is unable to make good use of the photons, most likely due to poor carrier collection efficiency. To measure the IQE, one first measures the EQE of the solar device, then
357:
Quantum efficiency (QE) is the fraction of photon flux that contributes to the photocurrent in a photodetector or a pixel. Quantum efficiency is one of the most important parameters used to evaluate the quality of a detector and is often called the spectral response to reflect its wavelength
324:
145:, one can evaluate the amount of current that the cell will produce when exposed to sunlight. The ratio between this energy-production value and the highest possible energy-production value for the cell (i.e., if the QE were 100% over the whole spectrum) gives the cell's overall
417:
348:
light (<400 nm and >1100 nm wavelengths, respectively); these wavelengths of light are either filtered out or are absorbed by the cell, thus heating the cell. That heat is wasted energy, and could damage the cell.
281:
398:). Responsivity is ordinarily specified for monochromatic light (i.e. light of a single wavelength). Both the quantum efficiency and the responsivity are functions of the photons' wavelength (indicated by the subscript λ).
821:
757:
272:{\displaystyle {\text{EQE}}={\frac {\text{electrons/sec}}{\text{photons/sec}}}={\frac {{\text{(current)}}/{\text{(charge of one electron)}}}{({\text{total power of photons}})/({\text{energy of one photon}})}}}
641:
358:
dependence. It is defined as the number of signal electrons created per incident photon. In some cases it can exceed 100% (i.e. when more than one electron is created per incident photon).
1076:
Delamarre; et al. (2013). Freundlich, Alexandre; Guillemoles, Jean-Francois (eds.). "Evaluation of micrometer scale lateral fluctuations of transport properties in CIGS solar cells".
879:
852:
695:
534:{\displaystyle QE_{\lambda }={\frac {R_{\lambda }}{\lambda }}\times {\frac {hc}{e}}\approx {\frac {R_{\lambda }}{\lambda }}{\times }(1240\;\mathrm {W\cdot {nm}/A} )}
668:
367:
from the
Institute of Researcher and Development on Photovoltaic Energy (IRDEP) who calculated the EQE mapping from electroluminescence measurements taken with a
182:
is the ratio of the number of charge carriers collected by the solar cell to the number of photons of a given energy that shine on the solar cell from outside
137:
value indicates the amount of current that the cell will produce when irradiated by photons of a particular wavelength. If the cell's quantum efficiency is
764:
700:
125:
A graph showing variation of internal quantum efficiency, external quantum efficiency, and reflectance with wavelength of a crystalline silicon solar cell.
583:
319:{\displaystyle {\text{IQE}}={\frac {\text{electrons/sec}}{\text{absorbed photons/sec}}}={\frac {\text{EQE}}{\text{1-Reflection-Transmission}}}}
1064:
921:
98:
329:
113:. A photographic film typically has a QE of much less than 10%, while CCDs can have a QE of well over 90% at some wavelengths.
109:
at each photon energy level. For typical semiconductor photodetectors, QE drops to zero for photons whose energy is below the
1171:
761:
Assuming each photon absorbed in the depletion layer produces a viable electron-hole pair, and all other photons do not,
134:
992:
172:
is the ratio of the number of charge carriers collected by the solar cell to the number of photons of a given energy
153:(MEG), quantum efficiencies of greater than 100% may be achieved since the incident photons have more than twice the
31:
1160:"7 - Advanced silicon radiation detectors in the vacuum ultraviolet and the extreme ultraviolet spectral range"
85:
hitting the device's photoreactive surface. As a ratio, QE is dimensionless, but it is closely related to the
1226:
1221:
895:
1211:
1166:, Woodhead Publishing Series in Electronic and Optical Materials, Woodhead Publishing, pp. 151–170,
150:
1159:
954:
73:
This article deals with the term as a measurement of a device's electrical sensitivity to light. In a
67:
1008:
Baker-Finch, Simeon C.; McIntosh, Keith R.; Yan, Di; Fong, Kean Chern; Kho, Teng C. (2014-08-13).
959:
857:
1216:
830:
35:
982:
673:
1231:
900:
146:
74:
1158:
Gottwald, Alexander; Scholze, Frank (2018-01-01), Nihtianov, Stoyan; Luque, Antonio (eds.),
1085:
1021:
933:
646:
8:
890:
1089:
1025:
937:
105:, QE is often measured over a range of different wavelengths to characterize a device's
26:
1140:
1101:
1167:
1105:
1047:
988:
570:
1144:
191:
measures its transmission and reflection, and combines these data to infer the IQE.
1132:
1119:
A. Delamarre; et al. (2014). "Quantitative luminescence mapping of Cu(In,Ga)Se
1093:
1037:
1029:
949:
941:
391:
63:
30:
A graph showing variation of quantum efficiency with wavelength of a CCD chip from
1009:
554:
395:
337:
562:
78:
1205:
1051:
368:
20:
1080:. Physics, Simulation, and Photonic Engineering of Photovoltaic Devices II.
379:
157:
energy and can create two or more electron-hole pairs per incident photon.
86:
341:
573:. Note that the unit W/A (watts per ampere) is equivalent to V (volts).
1097:
130:
106:
102:
1042:
1033:
945:
165:
Two types of quantum efficiency of a solar cell are often considered:
1136:
816:{\displaystyle {\frac {N_{e}}{t}}=\Phi _{\xi }{\frac {\lambda }{hc}}}
752:{\displaystyle {\frac {N_{\nu }}{t}}=\Phi _{o}{\frac {\lambda }{hc}}}
546:
77:(CCD) or other photodetector, it is the ratio between the number of
345:
154:
142:
138:
110:
121:
1010:"Near-infrared free carrier absorption in heavily doped silicon"
383:
90:
82:
328:
The external quantum efficiency therefore depends on both the
1065:
Silicon nanoparticle film can increase solar cell performance
636:{\displaystyle QE_{\lambda }=\eta ={\frac {N_{e}}{N_{\nu }}}}
881:= optical power absorbed in depletion layer, also in watts.
387:
94:
1007:
382:
is a similar measurement, but it has different units:
860:
833:
767:
703:
676:
649:
586:
420:
284:
197:
394:comes out of the device per unit of incident light
987:. Berlin Heidelberg: Springer. pp. 601, 603.
873:
846:
815:
751:
689:
662:
635:
533:
318:
271:
1203:
1157:
81:collected at either terminal and the number of
1118:
922:"2.5% efficient organic plastic solar cells"
1191:A. Rogalski, K. Adamiec and J. Rutkowski,
955:11370/108e619e-c6c2-4cf9-859e-6f937ac027f2
503:
1075:
1041:
953:
336:The ideal quantum efficiency graph has a
974:
374:
120:
25:
1164:Smart Sensors and MEMs (Second Edition)
919:
827:is the measurement time (in seconds),
1204:
980:
352:
174:shining on the solar cell from outside
52:incident photon to converted electron
1193:Narrow-Gap Semiconductor Photodiodes
854:= incident optical power in watts,
116:
13:
862:
835:
789:
725:
524:
515:
512:
505:
97:. Since the energy of a photon is
16:Property of photosensitive devices
14:
1243:
180:Internal quantum efficiency (IQE)
170:External quantum efficiency (EQE)
149:value. Note that in the event of
32:Wide Field and Planetary Camera 2
670:= number of electrons produced,
576:
70:of a magnetic tunnel junction.
1185:
1151:
1112:
1069:
1058:
1001:
913:
697:= number of photons absorbed.
528:
497:
401:To convert from responsivity (
361:
263:
255:
247:
239:
143:solar electromagnetic spectrum
1:
984:Handbook of Lasers and Optics
906:
874:{\displaystyle \Phi _{\xi }}
147:energy conversion efficiency
34:, formerly installed on the
7:
884:
151:multiple exciton generation
10:
1248:
1014:Journal of Applied Physics
18:
1125:Progress in Photovoltaics
847:{\displaystyle \Phi _{o}}
312:1-Reflection-Transmission
186:are absorbed by the cell.
66:, or it may refer to the
1123:thin-film solar cells".
690:{\displaystyle N_{\nu }}
234:(charge of one electron)
160:
89:, which is expressed in
19:Not to be confused with
926:Applied Physics Letters
981:Träger, Frank (2012).
920:Shaheen, Sean (2001).
875:
848:
817:
753:
691:
664:
637:
535:
390:(A/W); (i.e. how much
320:
273:
244:total power of photons
126:
99:inversely proportional
39:
36:Hubble Space Telescope
901:Solar-cell efficiency
876:
849:
818:
754:
692:
665:
663:{\displaystyle N_{e}}
638:
545:is the wavelength in
536:
414:(on a scale 0 to 1):
380:Spectral responsivity
375:Spectral responsivity
321:
274:
124:
75:charge-coupled device
64:photosensitive device
29:
858:
831:
765:
701:
674:
647:
584:
418:
299:absorbed photons/sec
282:
260:energy of one photon
195:
1227:Quantum electronics
1222:Physical quantities
1090:2013SPIE.8620E..09D
1026:2014JAP...116f3106B
938:2001ApPhL..78..841S
891:Counting efficiency
353:QE of image sensors
176:(incident photons).
1212:Engineering ratios
1195:, SPIE Press, 2000
1098:10.1117/12.2004323
871:
844:
813:
749:
687:
660:
633:
531:
316:
269:
135:quantum efficiency
127:
44:quantum efficiency
40:
1173:978-0-08-102055-5
1131:(10): 1305–1312.
1034:10.1063/1.4893176
946:10.1063/1.1345834
811:
783:
747:
719:
631:
571:elementary charge
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117:QE of solar cells
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1137:10.1002/pip.2555
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1062:
1056:
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998:
978:
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967:
958:. Archived from
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199:
1247:
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1201:
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1190:
1186:
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1152:
1122:
1117:
1113:
1074:
1070:
1063:
1059:
1006:
1002:
995:
979:
975:
965:
963:
918:
914:
909:
887:
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838:
834:
832:
829:
828:
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798:
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788:
774:
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766:
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739:
734:
728:
724:
710:
706:
704:
702:
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681:
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672:
671:
654:
650:
648:
645:
644:
625:
621:
615:
611:
609:
594:
590:
585:
582:
581:
579:
565:in vacuum, and
555:Planck constant
542:
519:
511:
504:
492:
481:
477:
475:
459:
457:
443:
439:
437:
428:
424:
419:
416:
415:
413:
410:, in A/W) to QE
407:
402:
377:
364:
355:
306:
293:
285:
283:
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279:
258:
250:
242:
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206:
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141:over the whole
119:
79:charge carriers
50:) may apply to
24:
17:
12:
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5:
1245:
1235:
1234:
1229:
1224:
1219:
1217:Photodetectors
1214:
1198:
1197:
1184:
1172:
1150:
1120:
1111:
1068:
1057:
1000:
993:
973:
911:
910:
908:
905:
904:
903:
898:
893:
886:
883:
868:
864:
841:
837:
809:
806:
802:
795:
791:
787:
782:
777:
773:
745:
742:
738:
731:
727:
723:
718:
713:
709:
684:
680:
657:
653:
628:
624:
618:
614:
608:
605:
602:
597:
593:
589:
578:
575:
563:speed of light
530:
526:
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489:
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469:
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9:
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3:
2:
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1115:
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1083:
1079:
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1066:
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1035:
1031:
1027:
1023:
1020:(6): 063106.
1019:
1015:
1011:
1004:
996:
994:9783642194092
990:
986:
985:
977:
962:on 2012-07-07
961:
956:
951:
947:
943:
939:
935:
931:
927:
923:
916:
912:
902:
899:
897:
896:DQE (imaging)
894:
892:
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882:
866:
839:
826:
807:
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736:
729:
721:
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707:
682:
678:
655:
651:
626:
622:
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612:
606:
603:
600:
595:
591:
587:
577:Determination
574:
572:
568:
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560:
556:
552:
548:
520:
508:
500:
493:
487:
482:
478:
472:
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440:
434:
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385:
381:
372:
370:
369:hyperspectral
359:
350:
347:
343:
339:
334:
331:
326:
303:
296:electrons/sec
290:
251:
228:
216:
209:electrons/sec
203:
185:
181:
178:
175:
171:
168:
167:
166:
158:
156:
152:
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144:
140:
136:
132:
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114:
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100:
96:
92:
88:
84:
80:
76:
71:
69:
65:
61:
57:
53:
49:
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22:
21:Quantum yield
1232:Spectroscopy
1192:
1187:
1177:, retrieved
1163:
1153:
1128:
1124:
1114:
1081:
1077:
1071:
1060:
1017:
1013:
1003:
983:
976:
964:. Retrieved
960:the original
929:
925:
915:
824:
760:
580:
566:
558:
550:
403:
400:
378:
365:
356:
338:square shape
335:
327:
189:
183:
179:
173:
169:
164:
128:
87:responsivity
72:
59:
55:
51:
47:
43:
41:
362:EQE mapping
342:ultraviolet
212:photons/sec
1206:Categories
1179:2020-08-19
1084:: 862009.
1078:Proc. SPIE
1043:1885/16116
932:(6): 841.
907:References
330:absorption
139:integrated
131:solar cell
107:efficiency
103:wavelength
68:TMR effect
1106:120825849
1052:0021-8979
867:ξ
863:Φ
836:Φ
801:λ
794:ξ
790:Φ
737:λ
726:Φ
712:ν
683:ν
627:ν
604:η
596:λ
509:⋅
494:×
488:λ
483:λ
473:≈
455:×
450:λ
445:λ
430:λ
224:(current)
42:The term
1145:98472503
885:See also
371:imager.
346:infrared
155:band gap
111:band gap
1086:Bibcode
1022:Bibcode
934:Bibcode
569:is the
561:is the
553:is the
392:current
384:amperes
101:to its
83:photons
1170:
1143:
1104:
1050:
991:
966:20 May
823:where
643:where
541:where
1141:S2CID
1102:S2CID
396:power
161:Types
62:of a
60:ratio
1168:ISBN
1048:ISSN
989:ISBN
968:2012
501:1240
388:watt
386:per
344:and
95:watt
93:per
91:amps
56:IPCE
1133:doi
1094:doi
1082:100
1038:hdl
1030:doi
1018:116
950:hdl
942:doi
309:EQE
287:IQE
200:EQE
184:and
133:'s
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1092:.
1046:.
1036:.
1028:.
1016:.
1012:.
948:.
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930:78
928:.
924:.
557:,
549:,
547:nm
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48:QE
1147:.
1135::
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840:o
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781:t
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217:=
204:=
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
