Al3+ doping into TiO2 photoanodes improved the performances of amine anchored CdS quantum dot sensitized solar cells

Abstract

Some quantum dot-sensitized solar cells (QDSSCs) were fabricated by doping Al3+ ions into the TiO2 and addition of amine (ethylglycinate hydrochloride) to the CdS solution in order to improve their efficiency. Results indicated that the photovoltaic parameters of the optimized cell were boosted compared with those of the reference cell which was free of Al3+ QDs and amine indicating 68, 73 and 10.40% improvements in efficiency, current density and open-circuit voltage, respectively. The electrochemical impedance spectra (EIS) proved that the electron life time was the most improved by 1.60 times in the optimized cell (τe=37.58ms) compared with that of the cell made only using pure TiO2 (τe=23.52ms). Thus, addition of 0.3%wt Al3+ as a dopant was appropriate to attain suitable photocurrent efficiency for the QDSSCs because it could be used in a minimum amount to improve the electron transport, drop the recombination and increase the cell efficiency.