Single MoS2-flake as a high TCR non-cryogenic bolometer

TL;DR

This paper presents a novel atomically thin MoS2-based bolometer with high temperature coefficient of resistance and low noise, achieved through a suspended design that enhances radiation absorption and thermal isolation.

Contribution

The study introduces a mechanically transferred suspended multilayer-MoS2 flake bolometer, eliminating complex fabrication and achieving high TCR and low NEP in ambient conditions.

Findings

TCR of approximately -9.5%/K achieved

Thermal noise-equivalent power around 0.61 pWHz-1/2

Effective thermal isolation due to suspended configuration

Abstract

Temperature coefficient of resistance (TCR) of a bolometer can be tuned by modifying the thermal conductance of an absorbing materials since they sense radiations via the temperature change in the absorber. However, the thermal conductance of the absorber can be reduced by engineering the appropriate thermal isolation, which can be an ultimate solution towards making a highly sensitive thermal detector. Here, we have developed an atomically thin 2D bolometer detector made up of a mechanically transferred suspended multilayer-MoS2 flake, eliminating the use of challenging thin-film fabrication process. The strength of our detector lies on the two factors: its large surface-to-volume window to absorb the radiations; the suspended configuration which prevents the heat dissipation through the substrate and therefore reduces the thermal conductance. The bolometric response of the detector is tested in both modes, via the photoresponse and the thermal response. The prototype is found to exhibit a very high TCR ~ -9.5%/K with the least achievable thermal noise-equivalent power (NEP) ~ 0.61 pWHz-1/2, in ambient conditions at 328 K.