Sb掺杂ZnTe薄膜结构及其光电性能

Structure and Photoelectric Properties of Sb-doped ZnTe Thin Films

采用真空蒸发工艺在玻璃衬底上制备了ZnTe和掺Sb-ZnTe多晶薄膜,并在氮气气氛中对薄膜进行热处理。分别利用XRD、SEM、紫外-可见分光光度计、霍尔效应测试仪对薄膜的晶体结构、表面形貌、元素组成以及光学、电学性能进行表征,研究Sb掺杂量和热处理对薄膜性能的影响。结果表明:未掺杂薄膜为沿(111)晶面择优生长的立方相闪锌矿结构,导电类型为P型。Sb掺杂并未改变ZnTe薄膜晶体结构和导电类型,但衍射峰强度降低;Sb含量直接影响着Sb在ZnTe中的存在形式,掺Sb后抑制了薄膜中Te和Zn的结合,使薄膜中Te的含量增加;室温下薄膜的光学透过率和光学带隙取决于掺Sb浓度和退火温度,并且掺Sb后ZnTe薄膜的载流子浓度显著增加,导电能力明显增强。

ZnTe and Sb-ZnTe polycrystalline thin films were prepared by vacuum evaporation on glass substrates and annealed in nitrogen environment. By using XRD, SEM, UV-VIS spectrophotometer and Hall effect measurements, the crystal structure, surface morphology, elemental composition, op- tical and electrical properties of the thin films were characterized, respectively, and the effects of Sb- doping amounts and heat treatment on the performance of the films were studied. The results show that pure ZnTe film is the cubic structure and preferentially orients in the （111） direction and its con- ductive type is P type. Sb-doping does not change the structure and conductive type of the films, but the intensity of diffraction peaks is lower than that of pure ZnTe films; the concentration of Sb direct- ly affects the form of Sb in the ZnTe. Sb doping inhibits the combination of Te and Zn, and leads to the increase of Te in the films. In addition,the optical transmittance and optical band gap of the films depend on the concentration of Sb and annealing temperature, and Sb-doping can also result in an ob- vious increasing of carrier concentration and reduce the resistivity, which significantly enhance the conductivity of the films.