氧分压对ZnO薄膜结晶质量和光学特性的影响

By using pulsed laser deposition method, ZnO films with excellent c-axis orientation were deposited on (100) silicon substrates at different oxygen pressure. The effect of oxygen pressure on the crystal quality and optical properties of ZnO thin films is studied with scanning electron microscope(SEM), X-ray diffrac-tion, room- temperature and variable-temperature photoluminescence (PL). It is found that the higher oxygen pressure is,the rougher the film is. In the oxygen pressure ranging from 0.2Pa up to 5.0Pa, the quality of films is improved with the increase of oxygen pressure while the quality of film decreases fast at the 10Pa. All the films show near-band emission at 3.29eV. The low-temperature PL spectra reveal that the 3.314eV PL peak is attributed to be from the transition of (D0, h). The corresponding energy level of the shallow donors is estimated to be 124meV below the conduction band minimum.