In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 15, No. 4 ( 2000-04), p. 880-883
Abstract:
We investigated the photoluminescence spectra as well as the crystal structure and optical energy gaps of the Zn 1- x Cd x Al 2 Se 4 single crystals grown by the chemical transport reaction method. It was shown from the analysis of the observed x-ray diffraction patterns that these crystals have a defect chalcopyrite structure for a whole composition. The lattice constant a increases from 5.5561 A for x = 0.0 (ZnAl 2 Se 4 ) to 5.6361 A for x = 1.0 (CdAl 2 Se 4 ) with increasing x, whereas the lattice constant c decreases from 10.8890 A for x = 0.0 to 10.7194 A for x = 1.0. The optical energy gaps at 13 K were found to range from 3.082 eV ( x = 1.0) to 3.525 eV ( x = 0.0). The temperature dependence of the optical energy gaps was well fitted with the Varshni equation. We observed two emission bands consisting of a strong blue emission band and a weak broad emission band due to donor–acceptor pair recombination in the Zn 1- x Cd x Al 2 Se 4 for 0.0 ⩽ x ⩽ 1.0. These emission bands showed a red shift with increasing x. The energy band scheme for the radiative mechanism of the Zn 1- x Cd x Al 2 Se 4 was proposed on the basis of the photoluminescence thermal quenching analysis along with the measurements of photo-induced current transient spectroscopy. The proposed energy band model permits us to assign the observed emission bands.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/JMR.2000.0125
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2000
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
