光电流
异质结
石墨烯
光电子学
材料科学
电场
量子效率
光子学
纳米技术
物理
量子力学
作者
Woo Jong Yu,Yuan Liu,Hailong Zhou,Anxiang Yin,Zheng Li,Yu Huang,Xiangfeng Duan
标识
DOI:10.1038/nnano.2013.219
摘要
Layered materials of graphene and MoS2, for example, have recently emerged as an exciting material system for future electronics and optoelectronics. Vertical integration of layered materials can enable the design of novel electronic and photonic devices. Here, we report highly efficient photocurrent generation from vertical heterostructures of layered materials. We show that vertically stacked graphene–MoS2–graphene and graphene–MoS2–metal junctions can be created with a broad junction area for efficient photon harvesting. The weak electrostatic screening effect of graphene allows the integration of single or dual gates under and/or above the vertical heterostructure to tune the band slope and photocurrent generation. We demonstrate that the amplitude and polarity of the photocurrent in the gated vertical heterostructures can be readily modulated by the electric field of an external gate to achieve a maximum external quantum efficiency of 55% and internal quantum efficiency up to 85%. Our study establishes a method to control photocarrier generation, separation and transport processes using an external electric field. Efficient photocurrent generation, which can be tuned by the electric field of a gate to reach both high external and internal quantum efficiencies, is shown to occur in vertical heterostructures comprising graphene, MoS2 and metals.
科研通智能强力驱动
Strongly Powered by AbleSci AI