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Perovskite-WS₂ Nanosheet Composite Optical Absorbers on Graphene as High-Performance Phototransistors.

ABSTRACT: High-responsivity phototransistors with a structure of perovskite-WS₂ nanosheet composite optical absorber and a reduced graphene oxide (rGO) channel layer is demonstrated via a facile and low-cost solution-processing method. The WS₂ nanosheets are dispersed within the perovskite matrix, forming the perovskite-WS₂ bulk heterojunction (BHJ). The hybrid phototransistor exhibits excellent figures of merit including high photoresponsivity of 678.8 A/W, high specific detectivity of 4.99 × 10¹¹ Jones, high EQE value of 2.04 × 10⁵% and rapid response to photoswitching. The high photoresponsivity could be attributed to the WS₂ nanosheets induced photo-generated electron-hole separation promotion effects due to the selective electron trapping effects in the WS₂ nanosheets, together with the high carrier mobility of the rGO channel. This work provides a promising platform for constructing high-responsivity photodetectors.

SUBMITTER: Zhang DD

PROVIDER: S-EPMC6518953 | biostudies-literature |

REPOSITORIES: biostudies-literature

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