Highly sensitive photodetector of Zn/Bi doped MAPbBr3 single crystals formed homojunction

The double doped MAPbBr3 single crystals (SCs) based homojunction is prepared by a modified solutionprocessed epitaxy growth method to tune the bandgap and form a larger energy band barrier for homojunction. The optoelectronics of a homojunction formed by epitaxial growing Zn/Bi doped MAPbBr3 SCs shows relatively lower trapped carrier density and higher built-in potential. Compared with pure MAPbBr3 SCs, the bandgap of Zn doped MAPbBr3 SCs become bigger while that of Bi doped MAPbBr3 SCs become smaller, which lead to a larger energy band barrier for the homojunction. The as-fabricated MAPbBr3 SCs based homojunction shows smaller dark current and excellent current stability compared to the pure MAPbBr3 SCs under external reverse voltage of 4 V. The doped MAPbBr3 SCs based homojunction displays highly sensitive characteristics, with a responsivity of 43 mA/W and a specific detectivity of 3.41x1013 Jones. These results confirm that the double doped MAPbBr3 SCs based homojunction is promising photodetector frameworks, which may be the key to realizing superior perovskite single crystal sensitive photodetector in the future.