Broadband Photovoltaic Detectors based on an Atomically Thin Heterostructure

TL;DR

This paper demonstrates a novel atomically thin heterostructure combining graphene with transition metal dichalcogenides for broadband photodetection from visible to short-wavelength infrared at room temperature, showing high sensitivity.

Contribution

The study introduces a new MoS2-graphene-WSe2 heterostructure that overcomes spectral range and absorption limitations of previous 2D material devices for broadband photodetection.

Findings

Achieved broadband detection from visible to short-wavelength infrared.

Demonstrated a specific detectivity of up to 10^11 Jones in near-infrared.

Operates effectively at room temperature.

Abstract

Van der Waals junctions of two-dimensional materials with an atomically sharp interface open up unprecedented opportunities to design and study functional heterostructures. Semiconducting transition metal dichalcogenides have shown tremendous potential for future applications due to their unique electronic properties and strong light-matter interaction. However, many important optoelectronic applications, such as broadband photodetection, are severely hindered by their limited spectral range and reduced light absorption. Here, we present a p-g-n heterostructure formed by sandwiching graphene with a gapless bandstructure and wide absorption spectrum in an atomically thin p-n junction to overcome these major limitations. We have successfully demonstrated a MoS2-graphene-WSe2 heterostructure for broadband photodetection in the visible to short-wavelength infrared range at room temperature that exhibits competitive device performance, including a specific detectivity of up to 1011 Jones in the near-infrared region. Our results pave the way toward the implementation of atomically thin heterostructures for broadband and sensitive optoelectronic applications.