Abstract:
In this research, we demonstrated the use of hafnium acetylacetonate (Hfaca) dissolved in ethanol as a buffer layer for perovskite solar cells from non-halide Pb (dehydrated lead acetate) source material. The inverted p-i-n planar heterojunction structure was employed in this work. A one step spin-coating method was used in depositing the perovskite solution before thermal annealing at 90 ○C for 5 min to form the perovskite film. Hfaca has been previously used as a buffer layer, but the optimal concentration has not been reported. The optimum concentration of Hfaca was found to be 1.0 mg/ml, resulting in a power conversion efficiency (PCE) of 12.23% corresponding to more than 30% improvement when compared to the control device (phenyl-C61-butyric acid methyl ester/Ag) without Hfaca, which has a PCE of 8.89%. Hfaca as a buffer layer leads to superior stability, retaining about 90% of its original PCE values after 15 days of storage in a glove box, compared to the control device, which retains 70% of the initial PCE value under the same storage
