Ultrafast Response of Monolayer Molybdenum Disulfide (MoS2) Photodetectors

TL;DR

This paper demonstrates that monolayer MoS2 photodetectors can achieve ultrafast response times of around 3 picoseconds, enabling extremely high bandwidths suitable for optical communication.

Contribution

It provides the first measurement of sub-5 ps response times in monolayer MoS2 photodetectors, highlighting their potential for ultrafast optoelectronic applications.

Findings

Response time as short as 3 ps

Photodetection bandwidth up to 300 GHz

Fast response due to short carrier lifetimes

Abstract

The strong light emission and absorption exhibited by single atomic layer transitional metal dichalcogenides in the visible to near-infrared wavelength range makes them attractive for optoelectronic applications. In this work, using two-pulse photovoltage correlation technique, we show that monolayer molybdenum disulfide photodetector can have intrinsic response times as short as 3 ps implying photodetection bandwidths as wide as 300 GHz. The fast photodetector response is a result of the short electron-hole and exciton lifetimes in this material. Recombination of photoexcited carriers in most two-dimensional metal dichalcogenides is dominated by non-radiative processes, most notable among which is Auger scattering. The fast response time, and the ease of fabrication of these devices, make them interesting for low-cost ultrafast optical communication links.