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Giant Circular Dichroism in Proximitized WS2 Spin-Valley Transistors for Complementary Optoelectronics and
Chengbiao Yang1, Min Liu1, Chenhao Zhang1
1Department of Physics, Engineering Research Center for Micro-Nano Optoelectronic Materials and Devices, Ministry of Education, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|September 20, 2025
Summary
Researchers developed a spin-valley transistor using WS2 that achieves high photocurrent polarization. This breakthrough enables complementary phototransistors and reconfigurable logic gates for optical computing.
Area of Science:
- Spintronics
- 2D Materials
- Optoelectronics
Background:
- Coupling spin and valley degrees of freedom in 2D materials is key for novel devices.
- Spin-valley transistors offer potential for advanced electronic and photonic applications.
Purpose of the Study:
- To demonstrate a highly polarized spin-valley transistor utilizing circular dichroic photocurrent in WS2.
- To break spin degeneracy in optical transitions and spin transport for enhanced device performance.
Main Methods:
- Integration of spin-selective tunneling spin detectors.
- Utilizing the magnetic proximity effect with spin-polarized substrates.
- Fabrication of a WS2-based transistor device.
Main Results:
- Achieved a giant photocurrent polarization of 41.90% at room temperature under UV light.
- Demonstrated reversal of circular dichroism sign by altering substrate/electrode magnetization.
- Observed opposite resistance states under circularly polarized light.
Conclusions:
- The developed device overcomes limitations for complementary phototransistors.
- Enabled construction of reconfigurable logic gates.
- Paves the way for optical couplers and on-chip optical computing.
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