Improving solar cells characteristics by tuning the density distribution of deep trapping states using Au@DLC decorated on photoanodes

Abstract

Quantum Dots Sensitize Solar Cells (QDSSCs) using photoanodes of porous titanium dioxide with CdS quantum dots are fabricated, and Au Nanoparticles (NPs) within a Diamond-Like Carbon (DLC) are doped. The overall power conversion efficiency (PCE) and short-circuit current density (Jsc) of 2.18% and 7.85 (mA/cm2) are being obtained, respectively. For TiO2/CdS/Au@DLC photoanode, which PEC shows a 47.2% enhancement compared with the TiO2/CdS photoanode. Raman spectra, UV–Vis absorbance, transport and trapping states of the samples studied in detail. Localized Surface Plasmonic Resonance LSPR effect of Au increased photon harvesting in QDSSCs which enhanced photocurrent and thus the cell performance. DLC increased photon harvesting and Jsc, which has multiple performances: total reflection, an electron barrier against the electrolyte and prevent Au NPs agglomeration in Au@DLC composite. The simulation of these photoanodes using Photo Electro Chemical Simulation (PECSIM) software is in good agreement with experimental data. As with the experimental results, TiO2/CdS/Au@DLC photoanode shows the highest PEC and Jsc, 3.38%, and 13.77 (mA/cm2) respectively.