Core-shell cadmium sulphide @ silver sulphide nanowires surface architecture: Design towards photoelectrochemical solar cells

Avinash C Mendhe; Sutripto Majumder; Nikila Nair; Babasaheb R Sankapal

doi:10.1016/j.jcis.2020.11.031

Core-shell cadmium sulphide @ silver sulphide nanowires surface architecture: Design towards photoelectrochemical solar cells

J Colloid Interface Sci. 2021 Apr:587:715-726. doi: 10.1016/j.jcis.2020.11.031. Epub 2020 Nov 12.

Authors

Avinash C Mendhe¹, Sutripto Majumder², Nikila Nair¹, Babasaheb R Sankapal³

Affiliations

¹ Nanomaterials and Device Laboratory, Department of Physics, Visvesvaraya National Institute of Technology, South Ambazari Road, Nagpur 440010, (M.S.), India.
² Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Republic of Korea.
³ Nanomaterials and Device Laboratory, Department of Physics, Visvesvaraya National Institute of Technology, South Ambazari Road, Nagpur 440010, (M.S.), India. Electronic address: brsankapal@gmail.com.

PMID: 33248697
DOI: 10.1016/j.jcis.2020.11.031

Abstract

Design and development of cadmium sulphide core with silver sulphide shell assembly in nanowire (NWs) surface architecture has been explored through room temperature, simple chemical route towards photoelectrochemical solar cell application. Incorporation of low band gap Ag₂S nanoparticles over the outer surface of the chemical bath deposited CdS NWs has been achieved by simple cation exchange route based on negative free energy of formation. Shell optimization has been performed by investigating structure, surface morphologies and optical analyses and correlated with the photovoltaic parameters. Interestingly, core-shell CdS NWs/ Ag₂S exhibits 1.5 better performance in terms of linear voltammetry, photocurrent transient response and the photo stability than bare CdS. Furthermore, three-fold enhancement in photoelectrochemical conversion efficiency have been observed for optimized FTO/ CdS NWs/Ag₂S compared to bare FTO/CdS NWs due to the augmented light harvesting and condensed charge recombination. External quantum efficiency exhibits 24% for the optimized CdS NWs/ Ag₂S core shell structure. Mott-Schottky and electrochemical impedance spectroscopy measurements have been used for better understanding the impact of gradual growth of Ag₂S over CdS NWs which directly influences the overall photocurrent density of the devices.

Keywords: Cation exchange, photoelectrochemical solar cells; Core–shell assembly; Nanowires.