Self-Powered Broadband Photodetector and Sensor Based on Novel Few-Layered Pd3(PS4)2 Nanosheets

Optoelectronics and sensing devices are of enormous
importance in our modern lives, which has propelled the scientific
community to explore new two-dimensional (2D) nanomaterials to meet
the requirements of future devices. Herein, we present the exfoliation of
palladium thiophosphate (Pd₃(PS₄)₂) by mechanical shear force exfoliation.
The Pd3(PS4)2-based photoelectrochemical (PEC) device demonstrated selfpowered
broadband photodetection in the range of 385−940 nm with an
unprecedented responsivity of 2 A W⁻¹ and a specific detectivity of about
8.67 × 10¹¹ cm Hz^1/2 W⁻¹ under the illumination of 420 nm LED light. The
crucial parameters such as photoresponsivity, response, and recovery time of
the device can be controlled by an externally applied voltage and the analyte
concentration. Moreover, Pd₃(PS₄)₂-based vapor-sensing devices exhibited
frequency-dependent selective acetone sensing in the presence of other
organic vapors with an ultrafast response and a recovery time of less than 1 s. Finally, the photocatalytic activity of Pd₃(PS₄)₂ was
revealed, which can be attributed to the presence of an appropriate band alignment with the catalytic activity of Pd. This novel
material with the aforementioned fascinating phenomenon will pave the way toward practical future applications in optoelectronics
and sensing.