Fig. 3: Optical cavity coupled to CH3NH3PbBr3 perovskite layer.

Photoluminescence (PL) spectra of CH3NH3PbBr3 perovskite out of the cavity (grey) and inside the cavity (green). Inset: Distributed Bragg Reflector (DBR)-based microcavity. The ultraviolet laser-assisted air passivation process is simplified by representing water molecules that passivate the trap centers in perovskite grains (orange/green cubes for bare/passivated CH3NH3PbBr3 grains).