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Ultrafast Carrier Dynamics and Bandgap Renormalization in Layered PtSe2
Gaozhong Wang1, Kangpeng Wang1,2, Niall McEvoy3
1School of Physics and AMBER, Trinity College Dublin, Dublin 2, Ireland.
Small (Weinheim an Der Bergstrasse, Germany)
|July 6, 2019
Summary
Few-layer platinum diselenide (PtSe2) exhibits semiconductor-like carrier relaxation, not metal-like. This thickness-dependent behavior has potential applications in ultrafast laser generation and optoelectronics.
Area of Science:
- Condensed-matter physics
- Materials science
- Nanotechnology
Background:
- Carrier interactions in 2D nanostructures are crucial for condensed-matter physics.
- These interactions are vital for optoelectronic and photonic applications.
Purpose of the Study:
- To investigate photoinduced carrier behavior in layered platinum diselenide (PtSe2).
- To understand carrier relaxation, chemical potential, and bandgap renormalization dynamics.
Main Methods:
- Ultrafast time-resolved pump-probe spectroscopy.
- Nonlinear optical measurements.
Main Results:
- PtSe2 demonstrates semiconductor-like carrier relaxation, distinct from metal-like behavior.
- Relaxation follows a triple-exponential decay with thickness-dependent times.
- A controllable band-filling effect was observed, dependent on layer number.
Conclusions:
- Few-layer PtSe2 exhibits unique carrier dynamics with potential for saturable absorption.
- Findings offer insights into many-body physics in 2D materials.
- Results pave the way for advanced optoelectronic and ultrafast photonic devices.
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