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High-Sensitivity Infrared Photoelectric Detection Based on WS2 /Si Structure Tuned by Ferroelectrics
Diyuan Zheng1, Xinyuan Dong1, Jing Lu2
1State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Key Laboratory for Thin Film and Microfabrication Technology of the Ministry of Education Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
Researchers enhanced infrared photodetection using a ferroelectric gate to tune tungsten disulfide (WS2) states. This method broadens absorption wavelengths and significantly boosts sensitivity and response speed for optoelectronic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Optoelectronics
Background:
- Tungsten disulfide (WS2), a transition-metal dichalcogenide, shows promise for optoelectronics but has limited infrared application due to its band gap.
- Improving sensitivity and extending spectral range are crucial for advanced infrared photodetection.
Purpose of the Study:
- To enhance infrared photodetection capabilities of WS2/Si junctions.
- To overcome the limitations of WS2's band gap for infrared applications.
- To investigate the effect of ferroelectric gating on photodetection performance.
Main Methods:
- Fabrication of WS2/Si junctions integrated with a P(VDF-CTFE) ferroelectric gate.
- Utilizing the polarization electric field of the ferroelectric gate to modulate WS2/Si junction states.
- Characterization of photodetection performance, including absorption wavelength range, sensitivity (Lateral Photovoltaic Effect - LPE), and response speed.
Main Results:
- The ferroelectric gate successfully broadened the absorption wavelength range to 405–1550 nm.
- Photodetection sensitivity, measured by LPE, significantly increased from 198.6 to 503.2 mV mm-1.
- The response speed of the photodetector was markedly improved due to increased carrier kinetic energy.
Conclusions:
- Ferroelectric tuning of WS2/Si junctions effectively enhances infrared photodetection.
- The observed improvements are attributed to WS2 band gap reduction and modulation of the interface potential barrier.
- This approach offers a pathway for developing high-sensitivity, ultrafast, and stable infrared photodetectors.
