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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. [ABSTRACT FROM AUTHOR]

Abstract: Group‐10 layered transitional metal dichalcogenides including PtS2, PtSe2, and PtTe2 are excellent potential candidates for optoelectronic devices due to their unique properties such as high carrier mobility, tunable bandgap, stability, and flexibility. Large‐area platinum diselenide (PtSe2) with semiconducting characteristics is far scarcely investigated. Here, the development of a high‐performance photodetector based on vertically aligned PtSe2‐GaAs heterojunction which exhibits a broadband sensitivity from deep ultraviolet to near‐infrared light, with peak sensitivity from 650 to 810 nm, is reported. The Ilight/Idark ratio and responsivity of photodetector are 3 × 104 and 262 mA W−1 measured at 808 nm under zero bias voltage. The response speed of τr/τf is 5.5/6.5 µs, which represents the best result achieved for Group‐10 TMDs based optoelectronic device thus far. According to first‐principle density functional theory, the broad photoresponse ranging from visible to near‐infrared region is associated with the semiconducting characteristics of PtSe2 which has interstitial Se atoms within the PtSe2 layers. It is also revealed that the PtSe2/GaAs photodetector does not exhibit performance degradation after six weeks in air. The generality of the above good results suggests that the vertically aligned PtSe2 is an ideal material for high‐performance optoelectronic systems in the future. [ABSTRACT FROM AUTHOR]