衬底温度对脉冲激光沉积制备ZnO性能的影响

Effect of substrate temperature on the properties of ZnO prepared with pulsed laser deposition method

脉冲激光沉积技术易于获得高质量的氧化物薄膜，目前已成为一种重要的制备ZnO薄膜的技术。为了获得高质量的ZnO薄膜，采用脉冲激光沉积（KrF准分子激光器：波长248nm，频率5Hz，脉冲宽度20ns）方法，在氧气气氛中以高纯锌（含Zn的质量分数为0．99999）为靶材、在单晶硅和石英衬底表面得到了ZnO薄膜。通过Z射线衍射仪、表明轮廓仪、荧光光谱仪、紫外可见分光光度计对合成薄膜材料的晶体结构、厚度、光学性质等进行了研究，分析了衬底温度变化对其性能的影响。结果表明，使用脉冲激光沉积法在600℃下可以制备出（002）高度结晶取向、透过率高于75％的近带边发射的高质量ZnO薄膜。

Pulsed laser deposition （PLD） method is a hot point in all kinds of preparing ZnO thin films methods because of obtaining high quality ZnO thin films easily. In the laboratory, ZnO film was prepared on the substrates of single crystal silicon （Si） and quartz respectively by means of PLD. The parameters of KrF excimer laser were 248nm wavelength, 5Hz pulse frequency and 20ns pulse duration. The high pure Zn（ mass fraction is 0.99999） was used as a target. Six samples of ZnO thin films were prepared at different substrate temperatures of room temperature （27~C） , 150~C, 300~C , 450~C, 600~C, 750~C in 02 atmosphere. The crystal structures of ZnO thin films were studied by means of X-ray diffraction, optical properties of ZnO thin films were studied by means of photoluminescenee spectra and ultraviolet-visible spectrophotometry. The effects of different substrate temperatures on crystal structures, thicknesses and optical properties of ZnO films were discussed. It is obvious that at the temperature of 600℃, high quality of ZnO thin films in （002） perfect structure can be obtained with more than 75% of near band emission .