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Detection of Nonradiative Recombination Centers in GaPN (N:0.105%) by Below‐Gap Excitation Light
Author(s) -
Ferdous Sanjida,
Kamata Norihiko,
Yagi Shuhei,
Yaguchi Hiroyuki
Publication year - 2020
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201900377
Subject(s) - recombination , excitation , band gap , quenching (fluorescence) , cascade , atomic physics , materials science , nitrogen , fermi level , molecular physics , chemistry , optoelectronics , fluorescence , physics , optics , biochemistry , organic chemistry , electron , chromatography , quantum mechanics , gene
Investigation on cascade photo‐excitation via intermediate band (IB) is promising for improving the efficiency of IB‐type solar cells (IBSCs). Increasing nitrogen (N) concentration in GaP changes an ensemble of discrete N–N pair levels to form the IB as well as introducing defect levels acting as nonradiative recombination (NRR) centers. In continuation of detecting NRR centers in GaP 1− x N x ( x > 0.5%), a study is made for the lower N concentration region of 0.105% to understand an original formation of defect levels and their properties. Elimination of temperature quenching by immersing the sample into liquid nitrogen reveals a distribution of NRR centers inside the forbidden energy gap and the shift of Fermi energy depending on above‐gap excitation (AGE) density. Profound understanding of IB and defects of GaP 1− x N x leads to a proper optimization of IBSCs.