Fabrication of MAPbBr₃ Single Crystal p‐n Photodiode and n‐p‐n Phototriode for Sensitive Light Detection Application

Abstract In this study, MAPbBr₃ single crystal (MSC) p‐n perovskite homojunction photodiode and n‐p‐n phototriode are successfully fabricated through controlled incorporation of Bi³⁺ ions in solution. Optoelectronic analysis reveals that the photodiode shows typical photovoltaic behavior and the best photovoltaic performance can be achieved when the n‐type MSC is grown in 0.3% Bi³⁺ feed solution. The as‐assembled p‐n MSC photovoltaic detector displays obvious sensitivity to 520 nm illumination, with a high responsivity of up to 0.62 A W^‐1 and a specific detectivity of 2.16 × 10¹² Jones, which surpass many those of MSC photodetectors previously reported. Further performance optimization can be realized by constructing an n‐p‐n phototriode using the same growth method. The photocurrent magnification rate of the as‐fabricated n‐p‐n phototriode can reach a maximum value of 2.9 × 10³. Meanwhile, a higher responsivity of 14.47 A W^‐1, specific detectivity of 4.67 × 10¹³ Jones, and an external quantum efficiency of up to 3.46 × 10³ are achieved under an emitter–collector bias of 8 V. These results confirm that the present p‐n and n‐p‐n MSC homojunctions are promising device configurations, which may find potential application in future optoelectronic devices and systems.