Wide absorption spectrum and rapid response time of PEC photodetectors based on MoS₂–Se nanocomposites

Abstract

Photoelectrochemical (PEC) photodetectors convert light into electrical signals via PEC processes, providing high sensitivity, positioning them as promising candidates for next-gen optoelectronic devices. Over the past few years, there has been a significant interest in the field of photodetection regarding 2D materials, owing to their advantageous properties. In this study, the PEC photodetection of hydrothermally synthesized MoS₂–Se nanocomposites have been systematically tested. Structural analysis confirms the coexistence of MoS₂ and Se phases in the synthesized nanocomposites with crystallite sizes in the nanoscale dimension. Optical studies indicate that MoS₂–Se nanocomposites exhibit broadened absorption spectrum extending to UV region, unlike pure MoS₂ which absorbs solely in the visible region. This enhances their sensitivity for wide-band photodetectors with a small bandgap (1.01–1.34 eV). Optoelectronic study revealed superior performance of MoS₂–Se thin film PEC device with efficient photoresponse with a responsivity of 38.3 μA/W and fast response time of 0.12 s. The novelty of this research resides in the integration of these unique features in MoS₂–Se nanocomposites for PEC photodetectors, explored for the first time. The innovative aspect of this study involves employing spin coating to deposit 2D MoS₂–Se thin films, which enhances control over film thickness and uniformity, thereby resulting in improved responsivity and photocurrent.

Keywords:

• Electrochemical study
• hydrothermal
• nanocomposites
• PEC photodetectors
• rapid response time
• wide absorption

Acknowledgments

The authors gratefully acknowledge the crucial resources provided by Prof. Anand Srivastava, Vice Chancellor, Netaji Subhas University of Technology.

Disclosure statement

There are no competing interests among the authors.

Data availability statement

All the data set required for the current research are included within the manuscript and supplementary document.