Proceedings of International online conference on Hybrid materials and optoelectronic devices (HYBRIDOE)
DOI: https://doi.org/10.29363/nanoge.hybridoe.2020.023
Publication date: 4th December 2020
In this talk, I will introduce some works of our group on materials design and compositional engineering for high efficiency and highly stable perovskite solar cells (PSCs). First, through molecular design for hole transporting materials (HTMs), we developed a new, dopant-free conjugated polymer HTM called DTB with very simple molecule structure but excellent abilities on defect passivation on and hole extraction. The DTB based PSC has the PCE of 19.68% and the JSC achieved 25.75 mA/cm2, which was the world's highest level based on the dopant-free organic HTLs. Then we further developed an "inorganic + organic" double-layer HTL, achieving 22.0% efficiency with excellent light, humidity and temperature stability. Secondly, through material design of the perovskite absorb layer, we successfully incorporated GABr into the perovskite material which can suppress the oxidation of Sn2+ ions. Consequently, the ideal-bandgap (1.35eV) Sn/Pb perovskite solar cells with GABr doping can have the PCE of 20.6%, which is the highest efficiency among all values reported to date for ideal-bandgap Sn/Pb PSCs. Thirdly, we developed a high-throughput inkjet printing based technique for high speed perovskite composition screening, which can fabricate 30-50 high-quality mixed perovskite films in several minutes, and the corresponding film properties database allowed to accelerate the screening and optimization of perovskite compositions. As a demonstration, we screened 30 tribromide perovskite materials, and these accelerated optimized novel compositions yield a high open-circuit voltage exceeding 1.5 V.