导　　师： 宁兆元

学科专业： 080501

授予学位： 硕士

作　　者： ;

机构地区： 苏州大学

摘　　要： ZnO 薄膜是一种直接宽带隙半导体材料,具有多种用途,可广泛的应用于太阳能电池、压电薄膜、光电器件、气敏器件和紫外探测器等方面。其特性可通过适当的掺杂来调剂。为了研究Ge 掺杂对ZnO 薄膜发光特性的影响,本文采用交替溅射和共溅射两种方法制备了Ge 掺杂ZnO 薄膜,分别对它们的结构和光致发光性质进行了研究。 一. 使用交替溅射的方法制备了Ge-ZnO 薄膜,研究了不同沉积功率、衬底对薄膜沉积速率的影响及退火温度对薄膜结构和光致发光谱的影响。随退火温度的升高,ZnO/(002/)衍射峰增强,表明薄膜的结晶度提高。样品在800℃和1000℃退火后,在XRD 谱中,出现了GeO 和GeO/_2 衍射峰。同时,在其光致发光谱中,出现了强的近紫外峰发射/(395nm/)及弱的黄峰发射/(590nm/)。395nm 处的近紫外峰可能同GeO 颜色中心及激子的复合相关,黄峰可能同Ge 的掺入有关。 二. 使用共溅射方法制备了Ge-ZnO 薄膜,研究了不同Ge 掺入量及退火温度对薄膜光致发光谱的影响,实验结果表明适当的Ge 掺入量可大大增强薄膜的蓝光发射,退火温度也是影响薄膜发光谱的一个重要因素。经过600℃退火,样品的光致发光谱中蓝峰减弱,出现了绿锋。蓝峰可能同薄膜中Ge 杂质形成的缺陷能级相关,而绿峰可能同薄膜中氧空位相关。 Zinc oxide films, a directly wide band gap semiconductor, have been actively studied because of its potential applications. It can be used in solar cells, piezoelectric device, optoelectric device, transparent conducting electrodes and gas sensors. The characteristics of ZnO films can be modulated by the appropriate dopant. To research the effects of Ge dopant on the photoluminescence of ZnO films, In this paper, we prepared Ge-doped ZnO films by alternative radio frequency magnetron sputtering and co-sputtering methods, and studied the their characteristics and luminescent properties. 1. Ge-doped ZnO films were prepared by alternative radio frequency /(RF/) magnetron sputtering. The influences of depositing condition on the depositing rate and annealing temperature on the film’s structure and luminescent properties were studied. With increasing temperature, the intensity of the ZnO/(002/) diffraction peak increases, indicating that the crystalline quality of the film improves. The samples annealed at 800 and 1000℃appear the GeO and GeO2 diffraction peaks, and the intensity of the near ultra-violet emission at 395 nm increases greatly, while a weak yellow emission appears at 590 nm. The near ultra-violet emission could be attributed to the GeO color centers and exciton recombination. The yellow peak is probably related to Ge incorporated in the ZnO structure. 2. Ge-ZnO films were prepared by the co-sputtering method. The influences of different Ge content and annealing temperature on PL spectrum were studied. The PL spectrum indicated that appropriate Ge content could greatly increase the intensity of blue emission, and the annealing temperature also was an important factor affecting the luminescent spectrum. After the sample annealed at 600℃, the blue emission increase, while there were green emission. The experimental result indicated that the blue emission was probably related to Ge dopant and the green emission was possibly correlated with oxygen vacancy.

关 键 词： 掺杂 薄膜 结构 光致发光

领　　域： [电子电信]