石墨烯晶体管基红外探测的根本机制与性能提高研究

This project faces the applications to advanced ultra-fast mid-infrared photo-detection， and investigates biased graphene transistor in the mid-infrared photo-detection mechanism and performance improvement, especially on the gate dielectrics, graphene/oxide interface, optimized metal/graphene contact and the origin of photocurrent. We will develop the process of graphene transistor and use the low pressure chemical vapor depostion to fabricate the graphene, and use atomic layer deposition to achieve high quality gate oxide/graphene interface,and use reliable ultraviolet photoelectron spectroscopy to obtain the work function of the metal/graphene contact directly, and use femto-second time resolved system to detect the real photocurrent origin. This project will provide the solution of key process in graphene/oxide interface and related physical model. This project also will clarify the photocurrent origin and the work function shift of the metal/graphene contact. Finally ,this project will achieve the prototype graphene transistor with high carrier mobility, broadband absorption and ultrafast response. This project has fundamental scientific value to the graphene mid-infrared photo-detection research.

本项目面向先进的超快中红外探测的应用,开展基于栅压下石墨烯晶体管基红外探测机制和性能提高的研究。特别对高质量栅介质和石墨烯/栅介质叠层界面制备、优化的金属/石墨烯接触和光生电流起源等关键问题深入研究。分别利用低压化学气相沉积制备可控层数大面积石墨烯和原子层淀积高质量石墨烯/栅介质界面结构。利用可靠的紫外光电子能谱直接获得金属/石墨烯接触后的金属功函数变化以及飞秒尺度泵浦-探测时间分辨系统进行光伏产生电子及热产生电子时间分辨及电子输运情况探测。从而解决石墨烯表面的原子层淀积高质量栅介质的关键工艺、获得抑制衬底声子散射和衬底/石墨烯界面相互作用的关键工艺和物理机制。测量栅压下石墨烯晶体管红外探测性能并在根本上厘清晶体管中光生电流根源， 阐释金属/石墨烯接触界面功函数变化及相关现象，最终获得栅压下石墨烯晶体管红外探测原型器件及性能优化方案。本项目具有原创性的研究价值和重要的实际意义。

本项目基于以石墨烯为代表的二维半导体面向超快中红外探测及在集成电路逻辑与存储的应用,开展了石墨烯晶体管基红外探测机制和二维半导体逻辑存储器件性能提高的研究。特别对高质量栅介质和石墨烯/栅介质叠层界面制备、优化的金属/石墨烯接触和低功耗存储技术等关键问题深入研究。利用低压化学气相沉积制备了可控层数大面积石墨烯和原子层直接淀积高质量石墨烯/栅介质界面结构。利用可靠的紫外光电子能谱直接获得金属/石墨烯接触后的金属功函数变化。从而解决石墨烯表面的原子层淀积高质量栅介质的关键工艺、阐释了金属/石墨烯接触界面功函数变化及相关现象。本项目具有原创性的研究价值和重要的实际意义，在AFM，Small，APL等国际学术期刊发表论文22篇，还有多篇论文待发表。