Li Xiaoqiang, Lin Shisheng, Lin Xing, Xu Zhijuan, Wang Peng, Zhang Shengjiao, Zhong Huikai, Xu Wenli, Wu Zhiqian, Fang Wei
Opt Express. 2016 Jan 11;24(1):134-45. doi: 10.1364/OE.24.000134.
In graphene/semiconductor heterojunction, the statistic charge transfer between graphene and semiconductor leads to decreased junction barrier height and limits the Fermi level tuning effect in graphene, which greatly affects the final performance of the device. In this work, we have designed a sandwich diode for solar cells and photodetectors through inserting 2D hexagonal boron nitride (h-BN) into graphene/GaAs heterostructure to suppress the static charge transfer. The barrier height of graphene/GaAs heterojunction can be increased from 0.88 eV to 1.02 eV by inserting h-BN. Based on the enhanced Fermi level tuning effect with interface h-BN, through adopting photo-induced doping into the device, power conversion efficiency (PCE) of 10.18% has been achieved for graphene/h-BN/GaAs compared with 8.63% of graphene/GaAs structure. The performance of graphene/h-BN/GaAs based photodetector is also improved with on/off ratio increased by one magnitude compared with graphene/GaAs structure.
在石墨烯/半导体异质结中，石墨烯与半导体之间的统计电荷转移会导致结势垒高度降低，并限制石墨烯中的费米能级调谐效应，这极大地影响了器件的最终性能。在这项工作中，我们通过将二维六方氮化硼（h-BN）插入石墨烯/GaAs异质结构中，设计了一种用于太阳能电池和光电探测器的三明治二极管，以抑制静态电荷转移。通过插入h-BN，石墨烯/GaAs异质结的势垒高度可从0.88 eV提高到1.02 eV。基于界面h-BN增强的费米能级调谐效应，通过对器件采用光致掺杂，石墨烯/h-BN/GaAs的功率转换效率（PCE）达到了10.18%，而石墨烯/GaAs结构的功率转换效率为8.63%。与石墨烯/GaAs结构相比，基于石墨烯/h-BN/GaAs的光电探测器的性能也得到了改善，其开/关比提高了一个数量级。
