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arXiv · 2203.12988

Hexagonal network of photocurrent enhancement in few-layer graphene/InGaN quantum dot junctions

Guanghui Cheng·Zijing Jin·Chunyu Zhao·Chengjie Zhou·Baikui Li·Jiannong Wang
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Abstract

Strain in two-dimensional (2D) materials has attracted particular attention owing to the remarkable modification of electronic and optical properties. However, emergent electromechanical phenomena and hidden mechanisms, such as strain-superlattice-induced topological states or flexoelectricity under strain gradient, remain under debate. Here, using scanning photocurrent microscopy, we observe significant photocurrent enhancement in hybrid vertical junction devices made of strained few-layer graphene and InGaN quantum dots. Optoelectronic response and photoluminescence measurements demonstrate a possible mechanism closely tied to the flexoelectric effect in few-layer graphene, where the strain can induce a lateral built-in electric field and assist the separation of electron-hole pairs. Photocurrent mapping reveals an unprecedentedly ordered hexagonal network, suggesting the potential to create a superlattice by strain engineering. Our work provides insights into optoelectronic phenomena in the presence of strain and paves the way for practical applications associated with strained 2D materials.

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Guanghui Cheng, Zijing Jin, Chunyu Zhao, Chengjie Zhou, Baikui Li, Jiannong Wang. 2022-03-24. Hexagonal network of photocurrent enhancement in few-layer graphene/InGaN quantum dot junctions. https://doi.org/10.1021/acs.nanolett.2c01766

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