Defects passivation via d-glucosamine hydrochloride for highly efficient and stable perovskite solar cells

The defects existing on surface and grain boundaries in organic-inorganic halide perovskite films are detrimental to both the performance and stability of perovskite solar cells (PVSCs). Here, an additive of Glucosamine hydrochloride (D-GH) is introduced into the perovskite precursor solution to achieve high power conversion efficiency (PCE) and long-term stability. It is found that D-GH additive can significantly improve of the quality of perovskite film with enhanced crystallinity, compact and smooth surface and slightly enlarged grain size, leading to reduced grain boundaries, trap densities and thus negligible hysteresis in the resultant PVSCs. The optimized devices with 0.05 mg/ml D-GH additive show the best device performance with an enhanced PCE of 20.30%, as compared to the control devices with the highest PCE of 17.77%. In addition, the stability of PVSCs with 0.05 mg/ml D-GH modification is much better than that of the reference one. Overall, this work demonstrates a green and cheap additive to fabricate highly efficient and stable PVSCs.