二维MoSe₂连续薄膜的化学气相沉积制备和退火研究

Preparation and Annealing of Two-Dimensional MoSe₂ Continuous Films by Chemical Vapor Deposition

摘要: 作为二维材料家族的典型代表，二维过渡金属硫族化合物在过去的十年受到了人们的广泛关注。二维MoSe₂是二维过渡金属硫化物中的重要一员，凭借其优异的电学和光学特性在多个领域中展现出巨大的应用潜力。本文采用化学气相沉积(chemical vapor deposition, CVD)法，通过不断优化实验参量，在同一衬底不同位置制备出了不同形状的MoSe₂薄膜，其中部分区域生长出大面积的MoSe₂双层连续薄膜，尺寸达到毫米级。CVD方法生长的MoSe₂薄膜不可避免地存在许多缺陷，这严重影响了其电学和光学性能。本文我们对MoSe₂连续薄膜进行了不同气氛和不同温度下的退火研究，实验表明在合适温度下退火可以有效提高CVD生长MoSe₂薄膜的晶体质量和光学性能。同时对基于MoSe₂双层连续薄膜的场效应管进行了退火前后电学特性研究，发现适当退火可以有效地提高器件的开关比和场效应迁移率。

Abstract: As a typical representative of the two-dimensional materials family, two-dimensional transition metal chalcogenides have gained extensive interest in the past decade. MoSe₂ is one of the most important transition metal sulfides, showing great application potential in many fields due to its excellent electrical and optical properties. MoSe₂ films with different shapes were synthesized on the same substrate at different locations by continuously optimizing the experimental parameters in the chemical vapor deposition (CVD). In some regions, large and continuous MoSe₂ bilayer films were grown with the size of mm. It is inevitable that MoSe₂ thin films grown by CVD have many defects, which seriously affect their electrical and optical properties. In this paper, we have studied the annealing of MoSe₂ continuous films under different atmosphere and different temperature. Annealing at appropriate temperature can effectively improve the crystal quality and optical properties of MoSe₂ films grown by CVD. At the same time, the electrical properties of the FET based on MoSe₂ continuous film were measured before and after annealing. The ON/OFF ratio and the mobility were improved obviously after annealing.