【作者】 吴彩文；

【导师】 李文；

【作者基本信息】 湘潭大学 ， 物理电子学， 2009， 硕士

【摘要】 半导体功能材料表面与界面光伏行为的研究是与太阳电池、发光材料、光催化、微/纳米光电子器件、光敏传感器等研究领域密切相关的,是表面和界面科学的前沿课题。对于具有光电互换功能的材料或器件来说,研究其光电活性与光伏行为性质的内在关系,以及影响微观光伏行为的结构与机制,对于新材料和新器件的开发与应用来说至关重要。近年来,具有低维结构的材料被引入使得大多数光电功能器件的光电活性与性能显著提高。研究光电功能材料,特别是微/纳米功能材料及其所构建的光电功能器件中表面与界面的光伏行为,是探讨其工作机理的基础,这也为设计电子或光电子器件及进一步优化器件体系的性能提供理论与实验依据。本文通过利用英国KP Technology公司制造的扫描Kelvin探针系统表征不同形貌结构ZnO的光伏行为。首先,综述了光电功能材料关于电子功函数与光伏行为的基础知识。接着,关于Kelvin探针在实验操作上提供了方便可行地进行仪器调试与准确测量的实验方法,以及测量结果修正的计算公式;分析了基底上生长稀疏微/纳米结构材料时,基底的表面电子功函数与稀疏微/纳米结构材料表面电子功函数是怎样影响Kelvin探针的测量结果,进而推导出了准确测量基底上稀疏微/纳米结构材料表面电子功函数的理论计算公式和实验方法;根据产生表面光电压的两种机制,建立了表面光电压与Kelvin探针测量结果之间的定量关系,并提供了测量表面光电压的实验方法。最后,用CVD方法在不同条件下制备了不同形貌与结构的ZnO样品和相关物理性质表征,用Kelvin探针对ZnO样品的电子功函数与表面光伏行为及衰减演化过程进行了跟踪测量,得出了CVD法制备的ZnO中,ZnO的表面电子功函数随蒸发区温度升高而减少、ZnO表面光电压的绝对值随着蒸发区温度升高而增大的结论;通过对ZnO样品表面光电压衰减演化过程测量数据的分析,得出了ZnO中不同的局域能级捕获的被激发光电子对稳定表面光电压有很大的贡献,以及ZnO中局域能级分布等相关的物理性质。更多还原

【Abstract】 The functional materials of the semiconductor with photoelectric properties will play a crucial role in the development of advanced science and technology in future, such as solar cells, luminscene materals, photocatalysis, micro/nano photoelectronic devices, optical sensor, etc, and those also are forward subjects. As far as the photoelectronic functional materials with function to transfer the energy between the optical energy and electric energy, the performance of the photoelectric functional materials is essentially determined by the intrinsic structure of the materials, which is mainly reflected by the photo-induced electron transition and transfer behavior in microscopic view, especially for developing the advanced materials with photo-to-electric converting function, it is of great significance to study the relationship between the photoelectric activity and the characteristics of the photo-induced charges and explore the mechanisms of influencing the behavior of the charges.In recent years, the introduction of low dimensional materials into various photoactive devices has been proved to promote their performance significantly. Therefore, it is essential to study the behaviors of the photo-induced charges at the interface and surface of the photoactive devices with low dimensional structure for exploring their novel operating mechanisms and constructing and optimizing the photoelectric devices with higher performance.The main thesis work is that the photovoltaic revolution of the ZnO with various structures and patters are characterized using the Kelvin probe(SKP, purchased from KP technology, UK). Firstly, basing on the principle and the system structure of Kelvin probe and the mechanism of forming surface photovoltage, explore a way to characterize quantitatively surface photovoltage simply and conveniently using Kelvin probe system; propose a theoretical and experimental way to measure precisely the work function and photovoltage revolution of the sparse micro/nano-structure materials grown on the substrate; the various ZnO samples are prepared by CVD method, their surface work function, stable photovoltage and its decay revolution are measured using Kelvin probe system, furthermore, the relevant photoelectric properties especially for the local levels of the samples are analyzed.更多还原