用脉冲激光沉积方法制备的ZnO薄膜的结构及光致发光特性

Structural and Photoluminescence Properties of ZnO Films Grown by Pulsed Laser Deposition Technique

在从室温到800℃的温度范围内,用脉冲激光沉积方法在Al_2O_3(0001)衬底上制备了ZnO薄膜。采用X射线衍射仪、原子力显微镜以及荧光光谱仪分别研究了衬底温度对ZnO薄膜表面形貌、结晶质量和光致发光特性的影响。X射线衍射仪和原子力显微镜的结果表明,当衬底温度从室温升高到400℃时,ZnO薄膜的结构及结晶质量逐渐提高,而当衬底温度超过400℃时,其结构和结晶质量变差;在400℃下生长的ZnO薄膜具有最佳的表面形貌和结晶质量。室温光致发光的测量结果表明,400℃下生长的ZnO薄膜的紫外发光强度最强,且发光波长最短(386 nm)。

ZnO films are deposited on A1203 （0001） substrates in the temperature range from room temperature to 800 ℃ by using a pulsed laser deposition （PLD） technique. The influence of substrate temperature on the surface morphology, crystallinity and photoluminescence properties of ZnO films is analyzed by using X-ray diffraction, atomic force microscopy and photoluminescence spectroscopy respectively. The result given by the atomic force microscopy shows that the structure and crystallinity of the ZnO films are improved gradually when the substrate temperature is increased from room temperature to 400 ℃ and are reduced when the substrate temperature is increased up to 400 ℃ The ZnO films grown at the temperature of 400℃ have the best surface morphology and crystalline quality. The measurement result obtained by photoluminescence spectroscopy at room temperature shows that the ZnO films grown at the temperature of 400℃ have the highest ultraviolet emission intensity at its shortest emission wavelength of 386 nm.