【摘要】 采用正入射的方法研究了生长在硅基片上的氧化锌薄膜的反射光谱,测量出氧化锌薄膜的光学吸收边在370nm,所对应的能量值为3 35eV。测量生长在石英玻璃基片上的氧化锌薄膜的透射光谱,得到相同的吸收边。表明ZnO薄膜的光学禁带宽度与体材料的禁带宽度一致。反射谱中,在550～600nm之间观察到一个吸收峰,吸收峰的位置以及吸收边的陡峭程度都随薄膜的结晶状况的不同而有所不同。更多还原

【Abstract】 Using DC reaction sputtering, ZnO films were deposited on Si and quartz substrates, respectively. The reflection and transmission spectra of ZnO films have been measured in order to detect the absorption edge and absorption peaks. A special system was designed to measure the reflection spectra of ZnO films deposited on Si substrates at vertical incidence. It is found that the ZnO films deposited on Si(100) or Si(111) substrates have the same absorption edge, whose wavelength is at 370nm, corresponding to energy of 335eV. This value is similar to the bandgap of ZnO crystal. Measuring the transmission spectra of ZnO films deposited on quartz substrates, the absorption edge is also at 370nm. It is indicated that the bandgap of ZnO film has no variance comparing to ZnO crystal. However, the absorption edge of ZnO film deposited on Si(100) substrate is sharper then that of ZnO film deposited on Si(111) substrate. We also found that the annealed sample has sharper absorption edge then that of unannealed sample. The reason is considered to the crystallinity of ZnO film. Higher crystal quality has sharper absorption edge. In the reflection spectra, an absorption peak was observed between 550nm and 600nm. The location of absorption peak is different for the ZnO film deposited on Si(100) substrate and for the ZnO film deposited on Si(111) substrate. We suggest that it is also resulted from the the difference of crystallinity of ZnO films.更多还原