Research On Additives And Interface Modification Of Organic-inorganic Hybrid Perovskite Solar Cells

In the last decade,organic-inorganic hybrid perovskite solar cells(PSCs)have made a breakthrough with a rapid increase in efficiency from 3.8%to 25.2%,which make them a very promising solar cell.The main factors currently limiting the commercial application of PSCs are device efficiency,stability,and large area manufacturing technology.The most effective performance improvement strategies are optimizing the perovskite light-absorbing layer and modifying the surface layer.Therefore,in this work,we mainly improved devices performance with the additive engineering and interface optimization.,which are mainly as follows.1.We add Ascorbic acid 2-glucoside(AA2G)that has reducibility to the TiO2 ETL prepared by chemical bath deposition to improve the charge separation efficiency and enhance the efficiency of perovskite solar cells,and propose a new type of additive to optimize ETL.During the experiment,the changes in the photoelectric properties of TiO2 ETL under the action of additives were first tested,and then the changes in the quality of the formamidine-based perovskite film were explored,and finally the improvement of the device performance was further explored.When the doping amount is 175 ?L,the oxygen defects of TiO2 ETL are reduced,the light transmission is enhanced,the crystallinity,light absorption,grain size and quality of the perovskite film have a better change.The research has shown that AA2G passivates the surface defects of TiO2 ETL and optimizes the quality of the film at the same time,so that the device efficiency is increased from 20.32%to 21.76%,and the stability is also significantly improved.2.We add organic molecular Paracyclophane(PCP)to the perovskite precursor solution to obtain high-quality perovskite films and high-performance PSCs,which provides a new type of additive for the additive engineering.The passivation modification effect of PCP is very significant.The crystal size of the perovskite film has been increased from 571 nm to 720 nm.At the same time,the crystallinity has been significantly enhanced.The effect of additives has significantly improved the quality of the perovskite film,and has clearly solved the problem of film defects and the number of grain boundaries.In the end,a champion PCE of 22.12%can be obtained when the doping concentration is 0.50 mg/mL.3.We treat the SnO2 ETL prepared by the low-temperature solution method with ultraviolet ozone(UVO)treatment to obtain a perovskite solar cell with the device efficiency of 20.16%.The SnO2 ETL modified by this optimization method forms a hydrogen bond with the perovskite light-absorbing layer,constructing a charge channel,which passivates the surface defects of the perovskite film,and reduces charge recombination.It provides a new viable solution for interface optimization and provides a potential strategy for large-scale production of flexible devices.