Study of black phosphorus quantum dot modified SnO2-based perovskite solar cells

Organic–inorganic hybrid perovskite solar cells are considered promising due to their strong light absorption capability, long carrier diffusion distance, and rapid increase in energy conversion efficiency in the past decade. However, there is a high concentration of defects between the perovskite layer and the electron transport layer, which can lead to limited carrier extraction and, thus, affect the device efficiency. Black phosphorus quantum dots (BPQDs) have the advantages of tunable bandgap size, high absorption coefficient, and high electron mobility. Therefore, we introduced black phosphorus quantum dots (BPQDs) in aqueous SnO2 colloidal solution by laser liquid-phase ablation to improve the carrier extraction rate and reduce the trap density. By characterizing the prepared complete devices, we found that the device efficiency reached 15.83% after the introduction of BPQDs, which is 12% higher compared to 14.06% for the blank sample. Our work provides a simple and fast method to enhance the efficiency of perovskite solar cells.