Mapping and characterization of surface-dependent electronic properties and morphological changes in the cubic phase of crystalline perovskite CsPbBr <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si213.svg" display="inline" id="d1e1311"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math>