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All-Inorganic Perovskite Quantum Dot-Monolayer MoS₂ Mixed-Dimensional van der Waals Heterostructure for Ultrasensitive Photodetector.

ABSTRACT: 2D transition metal dichalcogenide (2D-TMD) materials and their van der Waals heterostructures (vdWHs) have inspired worldwide efforts in the fields of electronics and optoelectronics. However, photodetectors based on 2D/2D vdWHs suffer from performance limitations due to the weak optical absorption of their atomically thin nature. In this work, taking advantage of an excellent light absorption coefficient, low-temperature solution-processability, and long charge carrier diffusion length, all-inorganic halides perovskite CsPbI_3- _x Br _x quantum dots are integrated with monolayer MoS₂ for high-performance and low-cost photodetectors. A favorable energy band alignment facilitating interfacial photocarrier separation and efficient carrier injection into the MoS₂ layer inside the 0D-2D mixed-dimensional vdWHs are confirmed by a series of optical characterizations. Owing to the synergistic effect of the photogating mechanism and the modulation of Schottky barriers, the corresponding phototransistor exhibits a high photoresponsivity of 7.7 × 10⁴ A W^-1, a specific detectivity of ?5.6 × 10¹¹ Jones, and an external quantum efficiency exceeding 10⁷%. The demonstration of such 0D-2D mixed-dimensional heterostructures proposed here would open up a wide realm of opportunities for designing low-cost, flexible transparent, and high-performance optoelectronics.

SUBMITTER: Wu H

PROVIDER: S-EPMC6299711 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

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