Hot Electron Injection into Semiconducting Polymers in Polymer Based-Perovskite Solar Cells and their Fate
Upon photoexcitation, metal halide perovskites are known to intrinsically possess long-lived hot electrons and holes. The nature of these hot carriers as well as their significance has recently been extensively studied. Using femtosecond laser transient absorption spectroscopy it was possible to investigate interfacial charge transfer – hot electrons and holes – between methylammonium lead iodide perovskite and titanium dioxide as well as several organic semiconducting materials used as hole transporting materials in perovskite solar cells. An unexpected carrier loss pathway was found, which consists in the injection of hot electrons into low LUMO level organic semiconductor organic materials, which may effect a change in the final photocurrent of efficient perovskite solar cells.