【作者】 张勇；

【导师】 唐东升；

【作者基本信息】 湖南师范大学 ， 物理电子学， 2014， 硕士

【摘要】 二维过渡金属硫化物二硫化钼(MoS2)是一种低维度宽带隙的半导体材料。单层的MoS2具有直接带隙(1.8ev)结构,适于构筑具有低静态功耗,高开关比特点的场效应晶体管。本论文采用“自上而下”的微机械剥离法制备单层或几层的类石墨烯二硫化钼纳米片,并对目标样品进行了拉曼光谱表征。利用光刻微加工、热蒸发镀膜等工艺,构筑了基于单层或多层MoS2纳米片的“金/MoS2纳米片/金”结构的半导体器件。利用2602源测系统结合LabVIEW编程语言实现了对MoS2薄膜器件在不同条件下的电输运性能的测试。取得的主要进展如下：1.通过微机械剥离法,成功剥离出单层MoS2样品。运用光刻微加工技术,成功构筑基于单层MoS2的半导体光电器件。2.用不同波长的激光照射MoS2纳米薄膜器件,发现MoS2具有优异的光敏特性。在蓝紫光照射下电流变化最大,绿光次之,红光最小,而且导电能力都瞬间增加了4个数量级。3.构筑了基于单层MoS2场效应晶体管,并研究了H2O分子吸附对MoS2场效应晶体管输运性能的影响。实验结果表明随着相对湿度增加,器件的导电性、开启电压和关断电压都相应增加。更多还原

【Abstract】 Two-dimensional transition metal sulfide, such as molybdenum disulfide (MoS2), is a low-dimensional semiconductor material with broad-band gap. Monolayer MoS2has direct band gap (1.8ev), which is a good candidate for building field-effect transistors with low quiescent power drain and high on-off ratio.In this paper,"top-down" micro-mechanical stripping method has been adopted to manufacture monolayer or multilayer grapheme-like molybdenum disulfide nanosheets, and Raman spectrum adopted to characterize the microstructures of the target products. Using photolithography and lift-off technique, Au/MoS2nanosheet/Au devices have been fabricated based on monolayer and multilayer MoS2nanosheets. The electrical transport properties of the devices have been characterized under different conditions on Keithley2602SourceMeter with Lab VIEW program. The main results of this paper are listed as follow:1. Monolayer MoS2nanosheets have been successfully exfoliated by micro-mechanical stripping method. Photoelectric devices based on monolayer MoS2have been successfully fabricated with photolithography. 2. We have measured the monolayer MoS2photoelectric properties of the devices under illumination of laser with different wavelength. Experimental results indicate that the MoS2devices exhibit excellent photosensitivity. The devices exhibit highest photosensitivity in the blue-violet light region, and then in green light region and in red light region. The conductivity of the MoS2devices increases over four orders of magnitude under light illumination.3. We have built field-effect transistors based on monolayer MoS2and studied the influences of H2O on the electrical properties the MoS2transistors. Experimental results show that the conductivity and the on and off voltages of the transistors increase correspondingly with relative humidity increasing.更多还原