Fig. 4: Structure and strain evolution of WBG PSCs under rapid solarthermal cycling conditions.

a Time-dependent operando GIWAXS plotted retrieved from azimuthal integrated line profiles for DP PSCs under thermal cycling conditions. b Zoom-in time-dependent operando GIWAXS, showing the reversible phase transition, indicated by the red dashed line. c Selected reshaped 2D GIWAXS data at 0 min and (d) at 12 min, showing the formation of new peaks. e Strain evolution extracted from the evolution of \({{{q}}}\approx 2.0\) Å−1 of control and DP devices. The strain is calculated according to the relative \(q\) shift divided by its original \(q\) value at 25 °C, f Schematic illustration of perovskite under rapid thermal cycling, showcasing tensile and compressive strain at high temperature and low temperature, respectively, and the phase transition at low temperatures.