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Improvement of strained InGaN solar cell performance with a heavily doped n + ‐GaN substrate
Author(s) -
Sumiya Masatomo,
Honda Tohru,
Sang Liwen,
Nakano Yoshitaka,
Watanabe Kenji,
Hasegawa Fumio
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201431732
Subject(s) - materials science , optoelectronics , heterojunction , doping , dislocation , piezoelectricity , solar cell , carrier lifetime , layer (electronics) , nitride , electric field , energy conversion efficiency , substrate (aquarium) , gallium nitride , wide bandgap semiconductor , silicon , nanotechnology , physics , composite material , oceanography , quantum mechanics , geology
We simulated III–V nitride heterojunction solar cells with a Mg‐doped GaN/intrinsic InGaN/Si‐doped GaN structure. We investigated the threshold dislocation density, the carrier lifetime, and the strain in the InGaN active layer. The conversion efficiency was sensitive to carrier lifetime limited by Shockely–Read recombination rather than the dislocation density. The electric field induced by the piezoelectric effect in the InGaN layer on +c polarity GaN was opposite to that in the depletion region. The recombination of photo‐generated carriers in the p‐GaN/i‐InGaN/ n‐GaN solar cell structure took place dominantly at the i/n interface even at 0 V, and the performance was remarkably degraded. It was found that this negative influence of the piezoelectric effect was reduced by a heavy doping of more than 3 × 10 19 cm −3 into the n + ‐GaN layer at the interface.