BaSnO₃ Electron-transporting Layer for Quantum Dots Solar Cells

Electronic transport layer plays a crucial role as a key component in emerging thin-film solar cells for the transportation of photo-generated electrons. In this study, we employed a simple co-precipitation method to synthesize well-sized BaSnO₃ (referred to as BSO) ternary nanocrystals. The impact of annealing temperature on the formation of BSO was studied. X-ray diffraction (XRD) results indicate that elevated temperatures are beneficial for reducing impurities, such as barium carbonate in BSO, thereby enhancing the phase purity of BSO nanocrystals. The synthesized BSO nanocrystals were applied as electron transport layer in PbS colloidal quantum dot solar cells. Performance of the devices with BSO synthesized at 1200 ℃ for 2 h surpassed that of the commercial TiO₂ nanocrystal. This improvement is mainly attributed to the efficient extraction of charges at the BSO/PbS quantum dot interface and low recombination at internal interfaces within the device.The optimal device exhibited the following characteristics: J_sc=25.199 mA·cm^-2, V_oc=0.480 V, FF=0.534 and PCE=6.454%, demonstrating excellent operational stability. It is confirmed for the first time that BaSnO₃ nanomaterials can be utilized as electron transport materials for quantum dot solar cells, providing theoretical and practical guidance for further advancements in the performance of similar devices in the future.