(Invited) Optically-Active Zero-Dimensional Graphene Quantum Dots with MoS2 for Photodetection

Abstract

With its superior electronic properties, large surface area, high mechanical strength-to-weight ratio, exceptional charge carrier mobility reaching the ballistic limit in certain cases, graphene is a material of immense technological importance. However, compared to other two-dimensional (2D) van der Waals solids, such as transition metal dichalcogenides (TMDCs) and black phosphorus, an atomic membrane of graphene absorbs less than about 2% of the incoming light due to its low light absorption cross-section, and lack of a bandgap. However, when sheets of graphene are physically confined into nanoscale dimensions, either as graphene nanoribbons or zero-dimensional (0D) structures, such as graphene quantum dots (GQDs), a band gap in such structures is induced due to quantum confinement. Additionally, semiconducting 2D materials such as MoS2, exhibit a distinct and well-defined band gap ranging from 1.3 eV to 1.8 eV, from bulk to monolayers. In this work, the hybrid structure of 0D graphene quantum dots (GQDs) and semiconducting 2D MoS2 has been investigated that exhibit outstanding properties for optoelectronic devices surpassing the limitations of bare MoS2 photodetectors.