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Multicolor Electroluminescence from Intermediate Band Solar Cell Structures
Author(s) -
López Nair,
Yu Kin Man,
Tanaka Tooru,
Walukiewicz Wladyslaw
Publication year - 2016
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201501820
Subject(s) - electroluminescence , materials science , optoelectronics , solar cell , multiple exciton generation , photovoltaics , electronic band structure , semimetal , band gap , photovoltaic system , condensed matter physics , nanotechnology , physics , layer (electronics) , ecology , biology
Intermediate band solar cells are a new generation of photovoltaics that allow for better utilization of the solar spectrum. The key and most challenging requirement for these cells is an efficient optical coupling between the intermediate band and the charge conducting bands. GaNAs based intermediate band solar cells have been used to generate electroluminescence. Two electroluminescence peaks are generated in the structure with electrically blocked intermediate band. The peaks are observed for both forward and reverse bias configuration and are attributed to optical transitions from the conduction to the intermediate band, and from the intermediate band to the valence band. The origin of the electroluminescence is confirmed by the temperature dependence of the electroluminescence peak energies that is consistent with the band anticrossing model of the intermediate band formation in dilute nitride alloys. This is the first direct observation of the optical transitions required for the operation of intermediate band solar cells. The results also demonstrate that properly modified intermediate band solar cell structures could be used as multicolor light emitters.