Application of AgInSe2 nanoparticles to boost the power conversion efficiency of CdS QDs-sensitized solar cells

Abstract

In this study, bandgap engineering was utilized to assess the efficiency of photoanodes incorporating CdS nanocrystals and AgInSe₂ (AISe) quantum dots (QDs) in quantum dot-sensitized solar cells (QDSSCs). Initially, the deposition of CdS(Xc) nanocrystal layers on a TiO₂ substrate was tested using the SILAR method with varying cycles (X = 1–6). Optical transmission analysis revealed a redshift in the absorption edge and reduced transmission with an increasing number of cycles. J-V analysis of TiO₂ NCs/CdS(Xc) photoanodes identified cycle X = 5 as optimal. The short-circuit current density (J_sc), open-circuit voltage (V_oc), fill factor (FF) and maximum power conversion efficiency (PCE) were 15.5 mA/cm², 614 mV, 40 %, and 3.76 %, respectively. Subsequently, pre-synthesized AISe QDs were deposited on TiO₂ nanocrystals/CdS(Xc) photoanodes, exhibiting a single absorption edge with a bandgap energy of 2.19 eV for all photoanodes. The TiO₂ NCs/CdS(5c)/AISe/ZnS photoanode showed an increase in J_sc and efficiency, reaching 17.25 mA/cm² and 4.27 %, respectively. Utilizing sub-micron-sized TiO₂ hollow spheres (HSs) as a light-scattering layer further enhanced light absorption and performance. It was demonstrated that this approach increased the photovoltaic parameters to a J_sc of 19.12 mA/cm², FF of 43 %, and an overall efficiency of 4.75 %.