Photoluminescent properties of Cd x Zn1−x O thin films prepared by sol-gel spin-coating method

Abstract

CdxZn1−xO thin films were prepared on Si (100) substrates by the sol-gel spin coating method. Temperaturedependent photoluminescence (PL) measurements were carried out to investigate the luminescent properties of the CdxZn1−xO thin films. The PL peaks of the CdxZn1−xO thin films decrease as the Cd concentration increases and the near-band edge emission (NBE) PL peaks of the CdxZn1−xO thin films are shifted toward the red region. In the temperature-dependent PL measurement, three components at 2.855, 3.038, and 3.148 eV in the PL emission peak of the Cd0.2Zn0.8O thin films were observed at 12 K. With increasing temperature, the emission peak at 3.148 eV at 12 K becomes red-shifted and the monotonic PL peak at 12 K divides into three clear peaks as the temperature increases. The activation energy for the 3.148 eV peak is 69.54 meV corresponding to the energy for the frozen-out donors.