Device Efficiency and Environmental Stability Before and After Interfacial Modification of Perovskite Solar Cells
Recently, Zhou Huiqiong's team at the National Nanosciences Center of the Chinese Academy of Sciences introduced the heparin sodium as a biopolymer into the cathode interface of perovskite solar cells. 2And MAPbI 3Layers act as molecular bridges, passivating interfacial defects, and at the same time improving the efficiency and stability of the device. The results of this study were reported recently as A Biopolymer Heparin Sodium Interlayer Anchoring TiO 2 And MAPbI3 Enhances Trap Passivation and Device Stability in Perovskite Solar Cells is published online in Advanced Materials magazine.
In recent years, organic-inorganic hybrid perovskite solar cells have caused research booms in the field of energy conversion due to their high-efficiency and low-cost characteristics. However, defects in the active layer or interface can seriously affect the device performance and stability of perovskite cells.
Zhou Huiqiong's team bridges TiO with heparin sodium molecules 2And MAPbI 3Layer, to study its effect on defect passivation and device attenuation. The introduction of this interface layer simultaneously passivates the bulk defects in the perovskite active layer and TiO 2 2/MAPbI 3The interface defects between the interfaces increase the device efficiency from 17.2% to 20.1%, and suppress the hysteresis loop phenomenon and charge-induced charge recombination. The stability of the modified device has also been greatly improved in the air. After standing for 70 days, it still maintains an initial efficiency of 85%. DFT theoretical calculations show that heparin sodium molecules pass through various functional groups (-COO-, -SO 3-, or Na+) and TiO 2In Ti4+, and MAPbI 3The interaction between Pb2+ and I- occurs. This study describes a highly simple and feasible method for the interface modification of perovskite cells using biomolecules to improve device performance.
The study was a further extension of Zhou Huiqiong's group research work (Chem. Eur. J. 2017, 23, 18140), with the National Nano Center's Shi Xinghua Group (theoretical calculations), Yan Xiaohui's research group (Kelvin probe test) and The Zhang Yuan Group of the Beijing University of Aeronautics and Astronautics (device physics test) worked together and the research work was supported by the Chinese Academy of Sciences 100-person plan and the National Natural Science Foundation of China.
