Interlayer Engineering in Halide Perovskite Solar Cells

Halide perovskite solar cells (PSCs) have a typical device structure of polycrystalline thin-film solar cells such as CdTe and CIGS solar cells. PSCs have surpassed the conventional polycrystalline thin-film solar cells, and now it has become an important issue whether low-temperature solution-processed polycrystalline PSCs can reach the radiative limit like epitaxial GaAs thin-film solar cells. In this talk, our recent approaches to improving the photovoltaic performance of PSCs in terms of the electrical and optical design of PSCs will be discussed. The local electric field design within the perovskite layer between charge transport layers (CTLs) by introducing a wide-bandgap halide layer enabled improved power conversion efficiency. In addition, the boosting radiation of the stacked perovskite layer between CTLs in the complete device by efficient reduction of interfacial non-radiative recombination could also bring performance gain by photon recycling and scattering. The electrical field and optical radiation design by interlayer engineering could be one of the strategies to reach the radiative efficiency limit. Our recent results of oxide CTLs will be discussed to improve the processability and long-term stability of PSCs.