Probing the effect of selenization on RF sputtered WSe2 thin films toward enhanced photoelectrochemical and photodetection performance
Ashish Waghmare, Mohit Prasad, Bharat Bade, Yogesh Hase, Pratibha Shinde, Shruti Shah, Ashvini Punde, Vidya Doiphode, Swati Rahane, Somnath Ladhane, Dhanashri Kale, Shashikant P. Patole, Sandesh Jadkar
Abstract
• RF sputtering of high quality WSe 2 thin films. • Improved structural, optical, and electrical properties by selenization. • A shift in flat band potential from 0.78 V to 0.89 V. • Photoresponsivity of 1.2 μA/W and photo detectivity of 9.5 × 10 5 jones. • Improved photocurrent and photoelectrochemical performance. Tungsten diselenide (WSe 2 ) is one of the promising two-dimensional materials among transition metal dichalcogenide (TMDCs) for its application in solar hydrogen production and optoelectronics devices. In this paper, we report the synthesis of WSe 2 thin films using RF-magnetron sputtering followed by post-selenizationin in purview of their use for photoelectrochemical (PEC) water splitting and photodetection applications. Characterization of selenized WSe 2 film shows improved structural, optical, and electrical properties compared to as-deposited WSe 2 film. The PEC evaluation shows that the selenized WSe 2 photocathode has improved photocurrent density, stability, and charge transfer properties compared to the as-deposited film. Furthermore, the selenized WSe 2 thin film photodetector demonstrated excellent performance, including better responsivity of 1.2 μA/W and detectivity of 9.5 × 10 5 Jones with enhanced response time under one sun illumination. These results highlight a simple fabrication approach for producing scalable and high-quality WSe 2 thin films for next-generation optoelectronics devices. The post-selenization step can effectively heal defects and optimize optoelectronic properties.