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Title: Investigation of deep-level defects in Cu(In,Ga)Se{sub 2} thin films by a steady-state photocapacitance method

The properties of defect levels located 0.8 eV above the valence band in Cu(In{sub 1−x},Ga{sub x})Se{sub 2} thin films were investigated by a steady-state photocapacitance method. When illuminated by light with a photon energy of 0.8 eV at 60 K, a fast increase, followed by a slow increase, was observed in the photocapacitance transients of all samples. Upon being re-exposed, samples with a low bandgap energy showed a slow decrease in photocapacitance transients. These observations were interpreted using a configuration coordinate model assuming two states for the 0.8 eV defect: a stable state D and its metastable state D* with a large lattice relaxation. The difference in the evolution mechanisms of the photocapacitance transients was attributed to the difference in the optical transition of carriers between the two states of the 0.8 eV defect and the valence and conduction bands.
Authors:
; ;  [1] ; ; ;  [2]
  1. Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)
  2. National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)
Publication Date:
OSTI Identifier:
22308153
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACTIVATION ENERGY; CAPACITANCE; CARRIERS; COPPER SELENIDES; CRYSTAL DEFECTS; D STATES; EV RANGE; EVOLUTION; GALLIUM COMPOUNDS; INDIUM COMPOUNDS; METASTABLE STATES; RELAXATION; STEADY-STATE CONDITIONS; TEMPERATURE RANGE 0013-0065 K; THIN FILMS; TRANSIENTS; VALENCE; VISIBLE RADIATION