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Interface-Induced WSe2 In-plane Homojunction for High-Performance Photodetection.
Jiawei Chi1,2, Nan Guo3, Yue Sun1
1Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, 100094, China.
Nanoscale Research Letters
|May 16, 2020
Summary
We developed a novel in-plane tungsten diselenide (WSe2) homojunction for high-performance photodetectors. This design achieves excellent responsivity, detectivity, and fast response times, offering a facile fabrication method.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- 2D transition metal dichalcogenides (TMDCs) are crucial for nano-electronics and nano-optoelectronics.
- Tungsten diselenide (WSe2) exhibits bipolar carrier transport and a suitable bandgap for photodetectors.
Purpose of the Study:
- To create a high-performance WSe2-based photodetector using an in-plane homojunction.
- To investigate the device's operating modes and performance metrics.
Main Methods:
- Fabrication of an in-plane WSe2 homojunction by selectively insulating parts of the WSe2 flake with hexagonal boron nitride (h-BN).
- Characterization of the device's photovoltaic and photoconductive properties under varying biases.
Main Results:
- The WSe2/h-BN/substrate structure successfully formed an in-plane homojunction.
- The device demonstrated dual-mode operation (photovoltaic and photoconductive).
- Achieved high responsivity (1.07 A/W), detectivity (>10^12 jones), and a fast response time (106 μs).
Conclusions:
- The substrate-gated in-plane WSe2 homojunction offers a facile and efficient approach for high-performance photodetectors.
- This method surpasses traditional chemical doping or electrostatic gating techniques.
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