Efficiency optimization of All-Inorganic perovskite solar cell device using NiO_x and ZnO as charge transport layers

In this study, we have developed and refined an all-inorganic perovskite solar cell with the structure FTO/ZnO/CsPbBr₃/NiO_x/Au. This was accomplished by incorporating the inorganic perovskite CsPbBr₃ and the inorganic charge transport layers ZnO and NiO_x. We employed solvent engineering techniques such as dropping solvents like isopropyl alcohol (IPA) and ethyl acetate (EA) during the spin-coating process, along with optimizing the thickness of the absorber layer and annealing conditions to enhance the power conversion efficiency (PCE). Our evaluation of the impact of the CsPbBr₃ absorption layer thickness on PCE revealed that efficiency improved with layer thicknesses up to 280 nm. Moreover, we investigated the influence of post-deposition annealing durations on CsPbBr₃, experimenting with times of 0.5hr, 1hr, 2hr, 3hr, and 5hr. The optimal conversion efficiency of 0.91 % was attained with an annealing temperature of 225 °C for 2hr, particularly when the absorption layer thickness was set at 280 nm. These results suggest that the device structure optimization for all-inorganic perovskite quantum dot solar cells can be successfully applied for efficiency optimization.