Effect of Different Ligands Coating on the Photovoltaic Performance of CdSe Quantum Dot-Sensitized Solar Cells

In this article, oleic acid (OA), oleylamine and tri-n-octylphosphine (OAm-TOP), and OA-TOP were used as ligands in the synthesis of CdSe quantum dots (QDs), respectively. Effect of three different ligands on the photovoltaic performance of CdSe QD-sensitized solar cells (QDSCs) is systematically investigated. Based on the results of UV-vis absorption spectra, it is confirmed that the absorption range is widen for CdSe QDs coated with OAm-TOP or OA-TOP compared with OA. Electrochemical impedance spectroscopy (EIS) study indicates that CdSe QDs synthesized using OAm-TOP or OA-TOP can better passivate the surface defects of QDs resulting in the improvement of photoelectric conversion efficiency (PCE) of devices. The optimized PCE of 3.6% was achieved for CdSe QDSCs modified with OAm-TOP.