Research of structural and optical properties of MgZnO films annealed at different oxygen partial pressures

摘要

Structural and optical properties of MgZnO films were investigated by annealing in oxygen at different pressures. The crystalline quality of the annealed films improves with increasing annealing pressure. After annealing at 3.03×10~5 Pa, the grain size became larger and oxygen content in the annealed films increased. This was attributed to the recrystallization of the films under high annealing pressure. However, a decreased oxygen content was found by annealing the films at 1.01 ×10~5 or 2.05×l0~(-3) Pa. According to the defect levels and the relationship between photoluminescence spectra and annealing conditions, it was suggested that the emission peak located at 2.270 eV in photoluminescence spectra was related to interstitial oxygen (O_i) which will compensate the donor defects (Zn;;or/and Vo) and lead to the MgZnO film transforming into a p-type conduction under the annealing pressure of 3.03 × 10 Pa.