Integration of Refractive Microlenses on BP/MoS2 Photodiodes for Enhanced Infrared Photodetection.

Abstract

The van der Waals materials have emerged as promising candidates for infrared (IR) photodetectors. Among these, black phosphorus (BP)/ molybdenum disulphide (MoS2) photodiodes have shown high specific detectivity at room-temperature. The signal-to-noise performance of such detectors can be further improved by employing a microlens to increase the total photon collection without changing the device size, and hence its noise current. In this study, we explore the direct integration of refractive microlenses on BP/MoS2 photodiodes, designed for operation at a wavelength of λ = 1.55 µm. The device's photoresponse is enhanced by up to 20× after microlens fabrication, enabling a detectivity of 1.8..