ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Enhancing the photo-sensing properties of CdS via fabricating hybrid with MoS₂ for bifunctional optoelectronic and DSSC applications

S. Kumaran, J. Seetha, K. Sudha, and G. S. Uthayakumar

Department of Electronics and Communication Engineering, Saveetha Engineering College, Chennai, India

E-mail: drkumaranece@gmail.com

Received: 13 July 2023  Accepted: 23 October 2023

Abstract:

Nowadays, researchers have shown great interest in the development of multifunctional materials for revolutionizing energy and electronic applications due to its potential to drive innovation, improve device performance, and pave the way for the next generation of advanced technologies. In this study, we synthesized CdS/MoS₂ mixed chalcogenide hybrid materials by novel ultrasonic-assisted solution technique which exhibit dual functionalities and have the ability to perform multiple tasks or demonstrate distinct behaviors simultaneously. The optical band gap energies were found to be 2.46 eV, 2.37 eV, 2.19 eV, and 2.05 eV for 0 wt. %, 2wt. %, 4 wt%, and 6 wt. % MoS₂/CdS, respectively, using UV results followed by Tauc’s plots. The formation hexagonal phase CdS was confirmed by X-ray diffraction analyses and Raman spectroscopic technique. The crystallite size was determined through Scherrer formula in 25–50 nm range. Scanning and transmission electron microscopy techniques have revealed that pure CdS exhibits a spherical morphology, while a core–shell structure is formed in the case of CdS/MoS₂. The surface area of the hybrid materials was calculated as 54.62 m²/g by using N₂ adsorption–desorption method. The optoelectronic parameters, including responsivity, external quantum efficiency (EQE), and detectivity, were investigated for as-synthesized samples. The results indicated that the CdS sample with 6% MoS₂ incorporation exhibited enhanced values of these optoelectronic parameters. Moreover, the electro-catalytic performance of fabricated hybrid samples was evaluated as counter electrodes for dye-sensitized solar cells (DSSCs). Due to its reduced band gap, increased surface area, inherent catalytic properties, and efficient charge transfer capabilities, CdS sample with 6% MoS₂ incorporation demonstrated outstanding electro-catalytic performance in the I⁻/I³⁻ redox reaction. Notably, the power conversion efficiency of CdMS-6 CE was found to be superior (PCE = 6.52%) compared to that of pristine CdS (4.18%). The findings suggest that diodes offer a more suitable approach for enhancing the performance of high-quality photodiodes and for the DSSC applications involving Pt-free counter electrodes.

Keywords: CdS/MoS2 hybrid photodetector; Optoelectronic properties; Counter electrode; DSSCs

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03171-x

Chemical Papers 78 (3) 1443–1456 (2024)