石墨烯/β-氧化镓肖特基结的制备及其日盲紫外探测性能研究

Solar blind ultraviolet photodetector has wide applications in missile warning and guide, communication, medicical treating, and so forth. This project addresses a solar blind photodetector based on graphene/β-Ga2O3 schottky junction with high sensitivity and fast response time. β-Ga2O3 is a wide bandgap (bandgap, 4.9 eV) semiconductor with high breakdown voltage and high avalanche gain, which is potential material for high performance solar blind photodetector. Graphene has high conductivity and mobility, which is helpful for realizing fast response photodetector due to fast carriers seperating and transporting. In this detector, schottky barrier of graphene/β-Ga2O3 could be adjusted by changing graphene work function. The performance of photodector could be also adjusted by schottky barrier. In the course of project, we plan to investigate the optoelectrical properties and growth mechanism of β-Ga2O3; The carrier multiplication effect of this schottky junction of graphene/β-Ga2O3 will be completely studied. In order to increase the detection efficiency, optical and eletrical properties and carriers transport of graphene/β-Ga2O3 schottky junction will be determined. A more complete study of this project will provide fundamental understanding and techniques of the increase of responsitivity of graphene/β-Ga2O3 schottky junction in solar blind ultraviolet photodetection application.

日盲紫外探测器在预警、制导等国防领域及通讯、医疗等民用领域有着巨大的应用前景。本课题以高灵敏度、快速响应的日盲紫外探测器为应用背景，提出以石墨烯/β-氧化镓（β-Ga2O3）肖特基结构实现日盲紫外探测器。β-Ga2O3的带隙为4.9 eV，具有击穿电场高、雪崩增益高等优点是日盲紫外探测器的优选材料；石墨烯的高导电性有利于快速分离和传输载流子，实现快速响应；通过调制石墨烯的功函数改变石墨烯/β-Ga2O3肖特基势垒高度和宽度，从而调制探测器的光响应特性。系统研究β-Ga2O3的光电性能和生长机制；研究该肖特基结的载流子倍增效应及光响应特性；研究石墨烯/β-Ga2O3肖特基结的光电性能随石墨烯功函数变化的影响规律，探讨探测器响应特性的影响因素，揭示其光学、电学及载流子传输性能等宏观性能与石墨烯/β-Ga2O3肖特基结构的内在联系，为我国高性能紫外探测器的研制打下坚实的理论和技术基础。

日盲紫外探测器在预警、制导等国防领域及通讯、医疗等民用领域有着巨大的应用前景。本课题以高灵敏度、快速响应的日盲紫外探测器为应用背景，提出以氧化镓（β-Ga2O3）肖特基结构实现日盲紫外探测器。β-Ga2O3的带隙为4.9 eV，具有击穿电场高、雪崩增益高等优点是日盲紫外探测器的优选材料。系统研究β-Ga2O3的纳米结构和薄膜的光电性能和生长机制；通过构建光电化学型氧化镓纳米柱肖特基结探测器和MSM型氧化镓薄膜日盲紫外探测器，研究载流子倍增效应及光响应特性；在本项目执行期间，制备了排列整齐的氧化镓纳米柱阵列和单一相β-Ga2O3薄膜，实现薄膜生长速率和膜厚可控，膜厚小于1μm厚度不均匀性不大于2%，实现薄膜具有择优取向，且x射线衍射半峰宽不大于0.5o的氧化镓薄膜样品；氧化镓纳米柱日盲紫外探测器在波长264nm处Rmax达到0.137mA/W，氧化镓薄膜日盲紫外探测器探测响应峰值位于259 nm峰值响应可到1.2A/W。为我国高性能紫外探测器的研制打下坚实的理论和技术基础。