Self-Powered, Ultra-thin, Flexible, and Scalable Ultraviolet Detector Utilizing Diamond-MoS$_2$ Heterojunction

TL;DR

This paper presents a novel, self-powered, flexible diamond-MoS$_2$ heterojunction UV detector with high responsivity, tunable response via bending, and scalable imaging capabilities, advancing UV sensing technology for flexible and integrated applications.

Contribution

It introduces the first large-scale, self-powered, flexible diamond UV detector integrated with MoS$_2$, enabling dynamic tuning and scalable imaging for the first time.

Findings

High responsivity of 94 mA W$^{-1}$ at 220 nm

Detectivity of 5.88 x 10$^9$ Jones

Successful demonstration of a 3x3 UV imaging array

Abstract

The escalating demand for ultraviolet (UV) sensing in space exploration, environmental monitoring, and agricultural productivity necessitates detectors that are both environmentally and mechanically resilient. Diamond, featuring its high bandgap and UV absorption, exceptional mechanical/chemical robustness, and excellent thermal stability, emerges as a highly promising material for next-generation UV detection in various scenarios. However, conventional diamond-based UV detectors are constrained by rigid bulk architectures and reliance on external power supplies, hindering their integration with curved and flexible platforms and complicating device scalability due to auxiliary power requirements. To tackle these challenges, herein, we firstly demonstrated a large-scale, self-powered, and flexible diamond UV detector by heterogeneously integrating a MoS$_2$ monolayer with an ultrathin, freestanding diamond membrane. The fabricated device operates at zero external bias, and simultaneously exhibits a high responsivity of 94 mA W$^{-1}$ at 220 nm, and detectivity of 5.88 x 109 Jones. Notably, mechanical bending enables strain-induced bandgap modulation of the diamond membrane, allowing dynamically tunable photoresponse-a capability absent in rigid diamond counterparts. To validate its practicality and scalability, a proof-of-concept UV imager with 3x3 pixels was demonstrated. This newly developed configuration will undoubtedly open up new routes toward scalable, integrable, flexible, and cost-effective UV sensing solutions for emerging technologies