Review—Photodetection Properties of Graphene/Silicon van der Waals Heterojunction

The integration of graphene with the bulk semiconductor leads to the formation of van der Waals heterojunction exhibiting distinctive electrical and optical properties which can overcome the intrinsic limitations of isolated two dimensional and three dimensional material based devices. This architecture results into the formation of a surface junction, that is, the depletion region is just well below the one atomic layer and therefore highly accessible photosensitive area. Graphene/Semiconductor junction based optoelectronic devices performing remarkably in the application areas of photodetection, chemical and biological sensing, optical communication and environmental monitoring etc. Especially, Graphene/Silicon van der Waals heterojunction based devices have achieved high photoresponsivity of 5.5 A W −1 with very high specific detectivity of 5.71 × 10 13 jones which is a great milestone in photodetection industry. Therefore, a thoroughly study of the physics behind the junction and potentiality of the performance of Graphene/Silicon junction based devices will be essential to serve as a basis for the study of more complex nanophotonic devices. Here, we review the state-of-the-art of the research work on the photodetectors based on Graphene/Silicon heterojunction through various modifications, such as introduction of native oxide layer or TiO 2 , Al 2 O 3 layer and with the integration of different types of nanostructures etc.