Investigating the physicochemical response of CdS quantum-dots deposition over SiO2-incorporated TiO2 photoanodes for solar cells

Abstract

There have been many attempts to enhance the performance of quantum-dot-sensitized solar cells (QDSCs) using various interfacial layers (ILs) which served as a passivation layer (PL), seed layer (SL), or blocking layer (BL), separately. Recent works revealed the tendency of these ILs to perform for multiple effects concomitantly, which need to be explored in depth to make used of QDSCs optimally. Herein, we deposited a SiO2 IL via successive ionic layer deposition and reaction (SILAR) method on a thin/mesoporous substrate, revealing the physichochemical influence of SiO2 IL in terms of enhanced deposition of CdS QDs as well as barricaded charge carrier recombination. Scanning electron- and atomic force- microscopic (AFM) techniques were used to affirm the aforementioned increase in QDs deposition while AFM coupled with contact angle measurements and electrochemical investigation (CV and EIS) confirmed the improved electrochemical response of SiO2 IL, which is speculated to originate increased performance (i.e. power conversion efficiency) of QDSCs.