基于氮化铝/石墨烯复合材料系统的高性能深紫外线探测器的研究

项目名称： 基于氮化铝/石墨烯复合材料系统的高性能深紫外线探测器的研究

项目编号： No.61505108

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 孙振华

作者单位： 深圳大学

项目金额： 20万元

中文摘要： 深紫外探测技术在现代社会有着广泛的应用，但现有的紫外探测器产品有着各自的缺陷。氮化铝(AlN)晶体以其超宽的直接能带带隙(6.1eV)和稳定的材料性质，成为深紫外(<205 nm)光电探测器的理想材料。然而其低下的载流子迁移率，严重地阻碍AlN在紫外探测领域的应用。申请者在之前的工作中，通过将载流子从光敏材料导入具有高迁移率的材料中进行传导，实现了光电探测效率的大幅提高。有鉴于此，本项目计划以AlN晶体为深紫外光敏材料，利用其宽能带带隙特性，同时，以石墨烯为载流子传导材料，利用其超高载流子迁移率，构建基于AlN/石墨烯复合材料的高性能深紫外光电探测器，力图实现在该光波段大于2000 A/W的创记录的光电响应度。在此基础上，通过对该复合材料系统在紫外辐射下光生载流子的产生、传输与输运过程的研究与理解，为进一步拓展AlN晶体在紫外光电器件领域的应用做实验和理论积累。

中文关键词： 氮化铝；深紫外光探测；石墨烯；复合材料；响应度

英文摘要： Ultraviolet photodetection (UP) devices are widely required in many aspects of modern society. But the traditional UP technologies severely suffer from their innate drawbacks in materials or structures. Aluminium nitride (AlN) crystal, a harsh-environment-stable semiconductor with a wide energy bandgap up to 6.1eV, is a perfect candidate for solar-blind (<280nm) deep ultraviolet photodetection applications. Nevertheless, the application of AlN in UP is hindered by its poor electrical properties, such as its low carrier mobility. To address this issue, this project proposes to use an AlN/grahene hybrid system instead of sole AlN crystal to fabricate UP devices. Graphene is a two dimensional material with super high carrier mobility and outstanding mechanical properties. Herein, graphene is supposed to play the role of carrier conductor and AlN crystals work as light absorber. In the photodetection process, AlN crystals absorb deep ultraviolet photons and generate carriers. These carriers should be injected into graphene and extracted from electrodes, generating photocurrent. Our previous research has proven the feasibility of this concept to bypass the low carrier mobility problem in light absorbing materials (AlN crystal in this project) by creating hybrid structures with high carrier mobility materials, thus realize high performance photodetection devices. Our preliminary investigation proves that the carrier injection from AlN to graphene is dynamically allowed. Here, we design several possible device configurations to attain optimum UP performance. With this concept, we expect a highly performing deep ultraviolet (<205nm) photodetection device with a record photoresponsivity beyond 2×103A/W. Moreover, we will deliberately study the generation, transport and transit processes of photo-induced carriers in the hybrid material system. The understanding of this physical mechanism will be of great significance for further research into ultraviolet optoelectronics application of AlN crystals.

英文关键词： aluminium nitride;deep ultraviolet photodetection;graphene;hybrid materials;responsivity