| dc.description.abstract | Perovskite solar cells (PSCs) based on organic-inorganic hybrid lead halide perovskite absorber has attracted great attention from the new generation PV community. PSCs has the characteristics of simple process, cheap material, and high power conversion efficiency. However, perovskite film prepared with solvent engineering, the crystallization cannot be controlled precisely. As a result, the film has many grain boundaries which affect the photovoltaic performance and long-term stability of the resulting photovoltaic devices. In this study, several Ruthenium dyes (such as N749, CYK-17, CYK-18, CYK-19) and organic dyes (such as BTI-3, BTI-19, INDT-1) were spin-coated on the top of the perovskite film to remedy the defects on the surface of the perovskite film to enhance the efficiency and stability of the cells. Among the above seven dye modifications, only N749, CYK-17 (ruthenium dyes) and BTI-19 (organic dye) can increase the efficiency of the cell. IR spectra evidenced the shift of absorption peaks of the carboxyl group (R-COOH) and thiocyanate (SCN) in the dye molecule suggesting the interaction between dye molecules and Pb+2 in perovskite. The contact angle of the perovskite film increases after modifying with dye molecules (Psk : 56.5o, Psk/N749: 75.6o, Psk/CYK-17: 75.6o, Psk/BTI-19: 78.8o) to create more hydrophobic surface. Consequently, the stability of the modified perovskite film as well as the corresponding devices enhanced. The photoluminescence intensity and life-time proved that dye modification can increase the life of the exactions and reduce the charge recombination of the perovskite film. The efficiency of the cell based on unmodified perovskite is 17.70% which is smaller than those based on dye-modified perovskite solar cell (Psk/N749(cell) : 19.62%, Psk/CYK-17(cell) : 18.66%, Psk/BTI-19(cell) : 19.08%). Furthermore, the longer stability of the cell based on dye modified absorber is better than that used unmodified perovskite absorber both in ambient atmosphere and glove box. | en_US |