Anomalous Visible Light Response in Organolead Bromide Perovskite

Figure captions: Synchrotron XRD patterns of MAPbBr3 obtained during compression up to 34.0 GPa.
Figure captions: Synchrotron XRD patterns of MAPbBr3 obtained during compression up to 34.0 GPa.

Dye-sensitized solar cells adopting organometal halide perovskites as light absorbers have recently emerged as a promising photovoltaic technology owing to their low material cost and excellent power conversion efficiency. Recent HPCAT experiments have shown an interesting photovoltaic behavior of organolead halides materials under high pressure.

Two phase transformations below 2 GPa (from Pm-3m to Im-3, then to Pnma) and a reversible amorphization starting from about 2 GPa were observed, which could be attributed to the tilting of PbBr6 octahedra and destroying of long-range ordering, respectively. Along with the amorphization process accomplished around 25 GPa, the resistance increased by 5 orders of magnitude while the system still maintains its semiconductor characteristics and considerable response to the visible light irradiation. (Wang et al, JACS, 137, 11144-11149, 2015)