TY - JOUR
T1 - Photoluminescence of CuGaS2 epitaxial layers grown by metalorganic vapor phase epitaxy
AU - Shirakata, Sho
AU - Chichibu, Shigefusa
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000/4/15
Y1 - 2000/4/15
N2 - High quality epitaxial layers of CuGaS2 have been grown on GaAs and GaP substrates by low-pressure metalorganic vapor phase epitaxy using cycropentadienylcoppertriethylphosphine, normal-tripropylgallium, and ditertiallybutyl sulphide precursors. Photoluminescence (PL) studies at 8 K have been carried out, and exciton-related PL peaks at 2.489 and 2.477 eV have been observed in addition to PL peaks at 2.43 (free-to-bound), 2.39 (donor-acceptor pair), and broad band at 1.65 eV. Temperature and excitation intensity dependences of the PL peaks have been studied in detail, and PL properties are compared with those for the bulk CuGaS2 crystals grown by the chemical vapor transport (CVT) method. PL spectra for nearly stoichiometric CuGaS2 epilayers exhibited the intense free exciton-related PL peak over the entire temperature range (8-300 K), which are in contrast to PLs dominated by defect-related deep peaks for Ga-rich or Cu-rich epilayers and the impurity related near-band edge PL for the CVT bulk crystal. These PL results show that the nearly stoichiometric CuGaS2 epilayers grown in this study are the highest quality reported so far.
AB - High quality epitaxial layers of CuGaS2 have been grown on GaAs and GaP substrates by low-pressure metalorganic vapor phase epitaxy using cycropentadienylcoppertriethylphosphine, normal-tripropylgallium, and ditertiallybutyl sulphide precursors. Photoluminescence (PL) studies at 8 K have been carried out, and exciton-related PL peaks at 2.489 and 2.477 eV have been observed in addition to PL peaks at 2.43 (free-to-bound), 2.39 (donor-acceptor pair), and broad band at 1.65 eV. Temperature and excitation intensity dependences of the PL peaks have been studied in detail, and PL properties are compared with those for the bulk CuGaS2 crystals grown by the chemical vapor transport (CVT) method. PL spectra for nearly stoichiometric CuGaS2 epilayers exhibited the intense free exciton-related PL peak over the entire temperature range (8-300 K), which are in contrast to PLs dominated by defect-related deep peaks for Ga-rich or Cu-rich epilayers and the impurity related near-band edge PL for the CVT bulk crystal. These PL results show that the nearly stoichiometric CuGaS2 epilayers grown in this study are the highest quality reported so far.
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U2 - 10.1063/1.372416
DO - 10.1063/1.372416
M3 - Article
AN - SCOPUS:0000270659
VL - 87
SP - 3793
EP - 3799
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 8
ER -