退火温度对MoS₂纳米薄膜特性影响研究

The Influence of Annealing Temperature on the Properties of MoS₂ Nanometer Thin Film

摘要: 本文主要采用化学气相沉积法，以MoS₂饱和溶液为原料，利用氩气为输运气体，携带MoS₂蒸汽进入反应室，在Si衬底上制备大面积均匀的MoS₂超薄薄膜，并分析了不同的退火温度对于薄膜表面形貌、吸收特性以及电学特性的影响。研究发现，经过850℃退火的二硫化钼薄膜平整，厚度和晶粒尺寸也逐渐均匀。另外，随退火温度升高，MoS₂超薄膜反射率降低，可显著提高器件光伏效应和光电转换效率，制备高效率的MoS₂/Si异质结太阳能电池。退火还可以改善薄膜的电学特性，经过850℃退火的薄膜，其导电率达到了2.848 × 10−4，霍尔迁移率高达6.42 × 102 cm 2V−1s−1，可用于制造超低待机功率的场效应管。通过分析不同退火温度对纳米MoS₂薄膜光电特性的影响，得出纳米MoS₂薄膜的最佳退火温度为850℃，这促进了MoS₂纳米电子器件的发展，推进了MoS₂在光电子领域以及信息技术方面的广泛应用。

Abstract: Molybdenum disulfide (MoS₂) thin films were deposited on Si substrates with MoS₂ saturated solution as a raw material carried by argon (Ar) gas by means of chemical vapor deposition. We have analyzed the influence of different annealing temperatures on surface morphology of films, absorption characteristics and electrical properties. We found that MoS₂ thin film annealled at 850˚C was characteristic of more smooth and symmetrical as compared to that of the unannealed sample. At the same time, the optical reflectivity apparently reduced, which indicated that annealing can effectively improve photovoltaic effect and photoelectric conversion efficiency, and can be used for fabricating solar cell. In addition, we found that the electrical properties of MoS₂ thin films had also been enhanced after annealing. We noted that the conductivity and the carrier mobility were up to 2.848 × 10−4 and 6.42 × 102 cm 2V−1s−1, when annealing at 850˚C, which shows promising potential for low power field effect transistor. Analyzing the influence of different an- nealing temperatures on photoelectric properties of MoS₂ nanometer thin films, we demonstrated that the best annealing temperature was 850˚C, which enhanced the applications of MoS₂ in the field of photoelectron and information techno- logy.