Design and Numerical Investigation of a Lead-Free Inorganic Layered Double Perovskite Cs₄CuSb₂Cl₁₂ Nanocrystal Solar...

In the last decade, perovskite solar cells have made a quantum leap in performance with the efficiency increasing from 3.8% to 25%. However, commercial perovskite solar cells have faced a major impediment due to toxicity and stability issues. Therefore, lead-free inorganic perovskites have been investigated in order to find substitute perovskites which can provide a high efficiency similar to lead-based perovskites. In recent studies, as a kind of lead-free inorganic perovskite material, Cs₄CuSb₂Cl₁₂ has been demonstrated to possess impressive photoelectric properties and excellent environmental stability. Moreover, Cs₄CuSb₂Cl₁₂ nanocrystals have smaller effective photo-generated carrier masses than bulk Cs₄CuSb₂Cl₁₂, which provides excellent carrier mobility. To date, there have been no reports about Cs₄CuSb₂Cl₁₂ nanocrystals used for making solar cells. To explore the potential of Cs₄CuSb₂Cl₁₂ nanocrystal solar cells, we propose a lead-free perovskite solar cell with the configuration of FTO/ETL/Cs₄CuSb₂Cl₁₂ nanocrystals/HTL/Au using a solar cell capacitance simulator. Moreover, we numerically investigate the factors that affect the performance of the Cs₄CuSb₂Cl₁₂ nanocrystal solar cell with the aim of enhancing its performance. By selecting the appropriate hole transport material, electron transport material, thickness of the absorber layer, doping densities, defect density in the absorber, interface defect densities, and working temperature point, we predict that the Cs₄CuSb₂Cl₁₂ nanocrystal solar cell with the FTO/TiO₂/Cs₄CuSb₂Cl₁₂ nanocrystals/Cu₂O/Au structure can attain a power conversion efficiency of 23.07% at 300 K. Our analysis indicates that Cs₄CuSb₂Cl₁₂ nanocrystals have great potential as an absorbing layer towards highly efficient lead-free all-inorganic perovskite solar cells.