Title: Effect of silver sulphide (Ag₂S) layer towards the performance of copper indium sulphide (CuInS₂) quantum dots sensitised solar cell

Authors: Nurul Syafiqah Mustakim; Suhaila Sepeai; Norasikin Ahmad Ludin; Mohd Asri Mat Teridi; Mohd Adib Ibrahim

Addresses: Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia ' Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia ' Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia ' Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia ' Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia

Abstract: The effect of Ag₂S as passivation layer is investigated in the CuInS₂quantum dot sensitised solar cell (QDSSC) application, which is used to improve the photovoltaic performance. In this study, Ag2S layers were deposited by using successive ionic layer adsorption and reaction (SILAR) deposition technique onto prepared TiO₂/CuInS₂ QDs thin films. The surface morphology, crystalline structure and optical properties of the samples were carried out using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD) and ultra-violet-visible near infrared spectrophotometry (UV-Vis). For electrical properties, Electrochemical Impedance Spectra (EIS), four-point probe and I-V test investigated the interfacial charge-transfer resistances, resistivity and conductivity of the samples. Results showed that the average particle size of the samples increased from 45.61 nm to 74.08 nm after the deposition of Ag₂S layer. The XRD results showed that the crystallite size of TiO₂/CuInS₂/Ag₂S photo anode estimated around 15.32 nm, while UV-Vis analysis indicated that the sample showed better light absorption capability compared to samples without the passivation layers. For electrical properties, TiO₂/CuInS₂/Ag₂S photo anode showed low resistivity values, thus, produced better conductivity of electrons. The performance of the solar cell was found to be improved with the presence of Ag₂S layer with power conversion efficiency of 0.136%. The obtained results showed that TiO₂ CuInS₂ QDs thin films with Ag₂S passivation layer are applicable as a photo anode in QDSSC applications.

Keywords: Ag₂S; CuInS₂; passivation; quantum dots; SILAR; successive ionic layer adsorption and reaction; solar cells.

DOI: 10.1504/IJNT.2020.112383

International Journal of Nanotechnology, 2020 Vol.17 No.11/12, pp.795 - 806

Published online: 13 Jan 2021 *

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