Reduced-graphene oxide decorated γ-In2Se3/Si heterostructure-based broadband photodetectors with enhanced figures-of-merit

Abstract

Recently, two-dimensional (2D) semiconductor-based broadband photodetectors have gained tremendous attention due to their immense potential applications in high-performance optoelectronic devices. In this report, we demonstrate a high-performance photodetector based on reduced-graphene oxide (rGO) decorated p-γ-In₂Se₃/n-Si heterostructures. The integration of rGO with a p-In₂Se₃/n-Si heterostructure results in an enhanced responsivity of ∼9.5 A W⁻¹ with detectivity of ∼2.39 × 10¹² cm Hz^1/2 W⁻¹ at −3 V under the illumination of 685 nm light with an intensity of 0.1 mW cm⁻². In addition, the rGO/In₂Se₃/Si heterostructure shows high sensitivity and fast response/recovery times (40/90 μs) with a broadband response ranging from visible to infra-red wavelengths, which makes it a suitable candidate for an efficient broadband photodetector. The enhanced figures-of-merit of the rGO/γ-In₂Se₃/Si heterostructure could be due to the increased optical absorption of incident light and effective separation of the photogenerated charge carriers because of the top rGO layer. Here, the rGO layer acts as an efficient hole transporting layer due to its high hole mobility, which effectively reduces the recombination of the photogenerated charge carriers.