Au ion beam engineered MXene incorporated TiO2 photoanodes for quantum dot sensitized solar cells

Abstract

In this study,TiO2 photoanodes are firstly incorporated with MXene at different concentrations (10 wt% − 40 wt%). Here, annealed MXene partially converts to TiO2and provide efficientlight scattering. The photoanode with optimized power conversion efficiency (PCE) is implanted by Au ion with fluence of 5 × 1012-–5 × 1015ions.cm−2. From the XPS spectra, it has been found that formation of ionic Au is more favorable at low fluence but after exceeding the solubility limit, metallic Au dominates. Enhancement in light harvesting and reduction in charge recombination of ionic Au based photoanodes has been observed through ultraviolet–visible and photolumiscencestudies respectively. The upward shifting of fermi level has been established on the basis of lower work function observed afterimplantation. As a result, QDSSC prepared with Au fluence of 5 × 1014ions.cm−2delivers83 % PCE enhancement as compared to TiO2based QDSSC due to combined effect of MXene incorporation and Au ion implantation.