激光照射对InSe结构及光电性质的作用研究

Effect of laser irradiation on the structure and optoelectrical properties of InSe

摘要:

InSe具有高载流子迁移率，在光电探测和场效应器件应用上具有非常好的前景．但InSe易于氧化，特别是在一定光和热激发下会氧化成In2O3．在InSe的研究中，拉曼光谱、荧光光谱等手段均需采用激光进行激发，目前激光照射测试过程对测试结果的影响并不清楚．通过采用拉曼光谱、原子力显微镜和开尔文探针显微镜，详细研究了激光照射过程对InSe拉曼光谱测试、表面形貌和表面电势的影响．结果表明：在激光功率为0.20 mW、曝光时间10 s的条件下，激光照射对材料基本没有影响；随着激光照射功率增强，激光诱导表面氧化而产生结构形变，拉曼光谱峰强下降，表面电势升高；随着高激光功率照射时间增长，表面的氧化程度迅速增加，但拉曼强度呈现先下降后增长再下降的变化，其原因来自于氧化层形态的变化．光谱测试对InSe材料产生不可忽略的影响，在材料分析中需要给予重视．

Abstract:

InSe shows high carrier mobility that is attracted in the application of photoelectric detection and field effect transistors. However， InSe is easy to oxide， especially under certain light and thermal excitation， it will oxidize to In2O3. In the research of InSe， Raman spectroscopy and fluorescence spectroscopy are conventional analytical methods that required laser excitation. At present， the influence of laser irradiation on the test results is not clear. In this study， the effects of laser irradiation on the Raman spectrum， surface morphology and surface potential of InSe were studied in detail by using Raman spectroscopy， atomic force microscope and Kelvin probe force microscope. It is found that laser irradiation has little effect on the material when the laser power is under 0.20 mW and exposure time of 10 s. With the increase of laser irradiation power， laser-induced surface oxidation induces structural deformation， decrease of Raman peak intensity and increase of surface potential. With the increase irradiation time of high laser power， the oxidation degree of the surface increases rapidly， but the Raman intensity decreases first， then increases， and then decreases again， which is due to the change of oxidation morphology. This research shows that spectral testing may have a non-negligible impact on InSe materials， which should be paid attention to in material analysis.