Perovskite materials have excellent optoelectronic properties, with high absorption coefficient, adjustable optoelectronic characteristics, and excellent bipolar transport capacity. At the same time, they also have the advantages of low material consumption, low component prices, and low investment costs, making perovskite photovoltaics more promising in application scenarios. Perovskite solar cells (perovskite SCs) have been widely studied as a promising photovoltaic technology, and the extraction and transfer of charge carriers are crucial for device performance.
The Li Yongfang/Meng Lei team from the Key Laboratory of the Institute of Mechanical and Solid State of the Chemical Research Institute of the Chinese Academy of Sciences has made continuous progress in the research of perovskite solar cells in recent years. Recently, the team proposed a local oxidation modification (LOE) strategy, which effectively controls and maintains the appropriate oxidation state of SnO2 by adding oxidants to the nano SnO2 electron transport layer, thereby achieving fine regulation of the electron transport layer (ETL). Researchers used ammonium chromate as an oxidant to compensate for excess oxygen vacancies and generate a p-type semiconductor Cr2O3 ultra-thin layer as a local reduction product. The formed Cr2O3/SnO2 nano p-n junction is conducive to charge extraction and reduces the non radiative recombination of the perovskite active layer at the buried interface. In addition, the addition of inorganic salts regulates the arrangement of SnO2 nanocrystals, forming Cr2O3 crystal domains and improving lattice matching, thereby achieving α- Vertical epitaxial growth of FAPbI3 crystals. Having Cr2O3/SnO2 ETL α- The FAPbI3 based perovskite solar cell achieved 25.72% PCE and achieved operational stability of T90>700h under continuous sunlight. The LOE strategy proposed in this study can be used for further experimental and theoretical research on the photovoltaic performance of ETL and pero SCs.
The relevant research results are published in the German Journal of Applied Chemistry.
Paper link
Electrical conductivity, electron transfer diagram, energy level diagram, and average electrostatic potential of Cr2O3/SnO2 thin films
