The temperature-dependent behavior of p-type transparent semiconducting oxide CuAlO2 single crystals prepared by using a flux self-removal method in alumina crucibles was investigated through transmittance and photoluminescence (PL) measurements at temperatures from 12 K to room temperature. The low-temperature (12 K) PL spectrum shows two weak, broad emission peaks, one at 3.52 eV and the other at 3.08 eV, which we assign to excitonic emission and to defectrelated emission originating from copper vacancies. The positions of the PL peaks as functions of temperature exhibit a normal behavior satisfying the standard Varshini law, and the Debye temperature is found to be θD = 610 ± 80 K. The exciton-binding energy of the CuAlO2 single crystal is estimated to be 49 meV from the PL intensity change with temperature.
Bibliographical noteFunding Information:
This work was supported by a National Research Foundation of Korea (NRF) Grant funded by the Korean Government’s Ministry of Education (MOE, 2009-0073366).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)