SQDs表面修饰TMDs的巨大负光电导效应研究

The photoelectric effect discovered by Hertz in 1887 is of great significance to the development, protection and applications of energy, environment and resources in today’s world. As a kind of photoelectric effect, a photoconductivity effect behaviors that the conductivity of the material is greatly increased under light irradiation. Based on this positive effect, humans develop a variety of applications. So far, however, due to the lack of the negative photoconductivity effect with a near equal value of a positive photoconductivity effect, the development and application of the device with a negative effect is only a dream. In this project, InAs, Si and Ge semiconductor quantum dots (SQDs), which are easy to capture or sceen carriers under light irradiation, are used to modify the two-dimensional (2D) layered transition metal dichalcogenides MoS2, MoSe2, WS2 and WSe2 (TMDs) with relatively small energy gaps and large specific surface area. Then we design it as field effect devices with a huge negative photoconductivity effect, and study its mechanism to develop a variety of optoelectronics logic computation devices. The success of this project will promote the development of advanced electronic materials in our country, and contribute to optical sensing, communication and computation

1887年赫兹发现的光电效应对当今全球的能源、环境和资源的开发、保护与应用具有重大意义。光电导效应属内光电效应的一种，光照射下此效应材料的电导率大为增加。基于这种效应，人类开发出各种应用。但是，迄今为止，与这种正光电导效应数值相当的负光电导效应一直缺席，相应器件的开发与使用仅仅是梦。本项目拟利用光照下易捕获或屏蔽载流子等特性的半导体性InAs、Si和Ge量子点 (SQDs)，修饰具有大比表面积和小能隙的硫系二维层状结构半导体MoS2、MoSe2、WS2和WSe2（TMDs），设计成场效应器件，得到巨大负光电导效应并研究其机制，开发出各种光控逻辑运算器件。本项目的成功，将促进我国在先进电子材料领域的发展，在光传感、光通讯、光计算等方面做出贡献。

制备多功能集成和高精度响应的光电半导体器件已成为光电检测普遍发展趋势。目前常规的正光电导器件很难满足人们的需求，研究负(或反)光电导效应具有重要意义。但是，迄今为止很少有研究者报道室温下具有超大电流降、大关/开比和超快响应速度的负光电导器件。本项目研究了在0.10V的低驱动偏压和360.0nm波长的激光照射下，不对称薄石墨烯(~12nm)/CsPbBr3量子点-p型GaN/厚石墨烯(~24nm)范德华双异质结构的巨大负光电导，其比率为~32.6，其响应/恢复时间为~100.0μs。这些来源于不对称石墨烯层对p型GaN表面能带调控、载流子传输及CsPbBr3量子点的增强。负光电导展示了其作为光电三元逻辑门的简化和多样性，为促进光电技术的发展提供了一种全新的策略。