Abstract
van der Waals (vdW) heterojunctions enable arbitrary combinations of different layered semiconductors with unique band structures, offering distinctive band engineering for photonic and optoelectronic devices with new functionalities and superior performance. Here, an interlayer photoresponse of a few-layer MoSe2/WSe2 vdW heterojunction is reported. With proper electrical gating and bias, the heterojunction exhibits high-sensitivity photodetection with the operation wavelength extended up to the telecommunication band (i.e. 1550 nm). The photoresponsivity and normalized photocurrent-to-dark current ratio reach up to 127 mA W−1 and 1.9 × 104 mW−1, respectively. The results not only provide a promising solution to realize high-performance vdW telecommunication band photodetectors, but also pave the way for using sub-bandgap engineering of two-dimensional layered materials for photonic and optoelectronic applications.
Original language | English |
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Article number | 1804388 |
Journal | Advanced Functional Materials |
Volume | 28 |
Issue number | 47 |
DOIs | |
Publication status | Published - 21 Nov 2018 |
MoE publication type | Not Eligible |
Funding
This research was supported by the Academy of Finland (276376, 284548, 295777, 304666, 312297, 312551, and 314810); TEKES (OPEC); the European Union’s Seventh Framework Program (No. 631610); China Scholarship Council; the International Science and Technology Cooperation Project of China (No. 2014DFR10780). The authors also acknowledge the provision of technical facilities of the Micronova, Nanofabrication Centre of Aalto University.
Keywords
- MoSe
- photodetectors
- sub-bandgap photodetection
- van der Waals heterojunction
- WSe