Structural defects and recombination behavior of excited carriers in Cu(In,Ga)Se{sub 2} solar cells

Journal Article · Mon Aug 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4961701· OSTI ID:22611392

Yang, J.; Du, H. W.; Li, Y.; Gao, M.; Wan, Y. Z.; Xu, F. ^[1]

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1. SHU-SolarE R&D Lab, Department of Physics, Shanghai University, Shanghai, 200444 (China)

The carriers’ behavior in neutral region (NTR) and space charged region (SCR) of Cu(In,Ga)Se{sub 2} thin film based solar cells has been investigated by temperature dependent photoluminescence (PL-T), electroluminescence (EL-T) and current-voltage (IV-T) from 10 to 300 K. PL-T spectra show that three kinds of defects, namely V{sub Se}, In{sub Cu} and (In{sub Cu}+V{sub Cu}), are localized within the band gap of NTR and SCR of CIGS layer, corresponding to the energy levels of E{sub C}-0.08, E{sub C}-0.20 and E{sub C}-0.25 eV, respectively. The In{sub Cu} and (In{sub Cu}+V{sub Cu}) deep level defects are non-radiative recombination centers at room temperature. The IV-T and EL-T analysis reveals that the injection modes of electrons from ZnO conduction band into Cu(In,Ga)Se{sub 2} layer are tunneling, thermally-excited tunneling and thermionic emission under 10-40, 60-160, and 180-300 K, respectively. At 10-160 K, the electrons tunnel into (In{sub Cu}+V{sub Cu}) and V{sub se} defect levels in band gap of SCR and the drifting is involved in the emission bands at 0.96 and 1.07 eV, which is the direct evidence for a tunneling assisted recombination. At 180-300 K, the electrons are directly injected into the Cu(In,Ga)Se{sub 2} conduction band, and the emission of 1.13 eV are ascribed to the transitions from the conduction band to the valence band.

• OSTI ID: 22611392
• Journal Information: AIP Advances, Vol. 6, Issue 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARRIERS
COPPER COMPOUNDS
DEFECTS
ELECTRIC CONDUCTIVITY
ELECTROLUMINESCENCE
ELECTRONS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
INJECTION
LAYERS
PHOTOLUMINESCENCE
RECOMBINATION
SELENIUM COMPOUNDS
SOLAR CELLS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
THERMIONIC EMISSION
THIN FILMS
TUNNEL EFFECT
ZINC OXIDES