Visualizing the Invisible in Perovskites

Halide perovskites are promising for a spectrum of energy applications including photovoltaics. Decisively characterizing microstructures of perovskites is critical yet challenging due to their soft characteristics. Recently, Rothmann et al. employed low-dose, low-angle annular dark-field scanning transmission electron microscopy to image perovskite thin films at the atomic scale, unveiling key structural details that are invisible to previous observations. This study opens the door to revealing microscopic structure-property-performance relationships in perovskites and beyond, guiding the reinvention and optimization of energy devices.