1. Optical generation of high carrier densities in 2D semiconductor heterobilayers
- Author
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Xiaodong Xu, Jue Wang, Frank Jahnke, Jenny Ardelean, Xiaoyang Zhu, James Hone, Yusong Bai, Alexander Steinhoff, Matthias Florian, and Mackillo Kira
- Subjects
Phase transition ,Materials science ,Exciton ,02 engineering and technology ,Electron ,7. Clean energy ,01 natural sciences ,Condensed Matter::Materials Science ,0103 physical sciences ,010306 general physics ,Research Articles ,Condensed Matter::Quantum Gases ,Multidisciplinary ,Condensed Matter::Other ,business.industry ,SciAdv r-articles ,Charge density ,Plasma ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter Physics ,021001 nanoscience & nanotechnology ,3. Good health ,Semiconductor ,Continuous wave ,Optoelectronics ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,business ,Excitation ,Research Article - Abstract
We realize Mott transition from interlayer exciton to charge-separated electron/hole plasmas in 2D WSe2/MoSe2 heterobilayers., Controlling charge density in two-dimensional (2D) materials is a powerful approach for engineering new electronic phases and properties. This control is traditionally realized by electrostatic gating. Here, we report an optical approach for generation of high carrier densities using transition metal dichalcogenide heterobilayers, WSe2/MoSe2, with type II band alignment. By tuning the optical excitation density above the Mott threshold, we realize the phase transition from interlayer excitons to charge-separated electron/hole plasmas, where photoexcited electrons and holes are localized to individual layers. High carrier densities up to 4 × 1014 cm−2 can be sustained under both pulsed and continuous wave excitation conditions. These findings open the door to optical control of electronic phases in 2D heterobilayers.
- Published
- 2019