Origin of High Efficiency and Long-Term Stability in Ionic Liquid Perovskite Photovoltaic
Microstructure characterization of perovskites. High-resolution transmission electron microscopy (HR-TEM) images of (a) MAAc perovskite (left: the magnified lattice fringes and FFT about the red frame region) and (b) DMF perovskite (right: the magnified lattice fringes and FFT about the red frame region). Conductive atomic force microscopy (c-AFM) and topological images of (c) MAAc perovskite and (d) DMF perovskite. (e) The structure diagram of grains and GBs in the MAAc perovskite. (f) The temperature-dependent conductivity of MAAc and DMF perovskite films for the activation energy () of ion migration.