Stabilized Wide Bandgap MAPbBrxI3-x Perovskite by Enhanced Grain Size and Improved Crystallinity

The light instability of CH3NH3PbIxBr3-x is one of the biggest challenges for its application in tandem solar cells. Here we show that an improved crystallinity and grain size of CH3NH3PbIxBr3-x films could stabilize these materials under one sun illumination, improving both the efficiency and stability of the wide-bandgap perovskite solar cells.