Cold plasma-synthesized carbon quantum dots for enhanced photovoltaic performance in quantum dot-sensitized solar cells

Abstract

The effect on the photovoltaic properties of the TiO2-based cadmium sulfide (CdS) quantum dot sensitized solar cells (QDSSCs) was investigated by incorporating carbon quantum dots (CQDs) synthesized via a cold atmospheric plasma method. CQD incorporated photoanodes were characterized by SEM, TEM, XRD, Raman spectroscopy, FTIR spectroscopy, PL spectroscopy, UV–visible spectroscopy, and Mott-Schottky techniques. TEM measurements revealed that the CQDs were mostly spherical with an average diameter of ∼3 nm. The presence of CQDs in the TiO2 photoanode was confirmed by both Raman spectroscopy and FTIR measurements. The findings from the PL and IPCE analyses showed that CQDs functioned as an energy down-converting material, broadening the responsive range of the CdS QDSSC to encompass higher energy photons. QDSSCs fabricated with CQDs-incorporated photoanode, a sulfide redox couple, and a Pt counter electrode exhibited a 31.3 % enhancement in power conversion efficiency, leading to a 1.68 % efficiency compared to the 1.28 % efficiency of the pristine TiO2 photoanode. Show more