Chip-integrated van der Waals PN heterojunction photodetector with low dark current and high responsivity

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Light: Science and Applications, Volume 11, issue 1
Two-dimensional materials are attractive for constructing high-performance photonic chip-integrated photodetectors because of their remarkable electronic and optical properties and dangling-bond-free surfaces. However, the reported chip-integrated two-dimensional material photodetectors were mainly implemented with the configuration of metal-semiconductor-metal, suffering from high dark currents and low responsivities at high operation speed. Here, we report a van der Waals PN heterojunction photodetector, composed of p-type black phosphorous and n-type molybdenum telluride, integrated on a silicon nitride waveguide. The built-in electric field of the PN heterojunction significantly suppresses the dark current and improves the responsivity. Under a bias of 1 V pointing from n-type molybdenum telluride to p-type black phosphorous, the dark current is lower than 7 nA, which is more than two orders of magnitude lower than those reported in other waveguide-integrated black phosphorus photodetectors. An intrinsic responsivity up to 577 mA W-1 is obtained. Remarkably, the van der Waals PN heterojunction is tunable by the electrostatic doping to further engineer its rectification and improve the photodetection, enabling an increased responsivity of 709 mA W-1. Besides, the heterojunction photodetector exhibits a response bandwidth of similar to 1.0 GHz and a uniform photodetection over a wide spectral range, as experimentally measured from 1500 to 1630 nm. The demonstrated chip-integrated van der Waals PN heterojunction photodetector with low dark current, high responsivity and fast response has great potentials to develop high-performance on-chip photodetectors for various photonic integrated circuits based on silicon, lithium niobate, polymer, etc.
Funding Information: This project was primarily supported by the National Key R&D Program of China (Grant Nos. 2018YFA0307200 and 2017YFA0303800), the National Natural Science Foundation of China (Grant Nos. 61905198, 61775183, 11634010, and 61675171), Key Research and Development Program in Shaanxi Province of China (Grant Nos. 2017KJXX-12, 2018JM1058, and 2018KW-009), the Fundamental Research Funds for the Central Universities (Grant Nos. 3102017jc01001, 3102018jcc034, and 3102017HQZZ022). Publisher Copyright: © 2022, The Author(s).
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Tian, R, Gan, X, Li, C, Chen, X, Hu, S, Gu, L, Van Thourhout, D, Castellanos-Gomez, A, Sun, Z & Zhao, J 2022, ' Chip-integrated van der Waals PN heterojunction photodetector with low dark current and high responsivity ', Light-Science & Applications, vol. 11, no. 1, 101 .