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Ultrafast Carrier Dynamics and Bandgap Renormalization in Layered PtSe 2
Author(s) -
Wang Gaozhong,
Wang Kangpeng,
McEvoy Niall,
Bai Zhengyuan,
Cullen Conor P.,
Murphy Conor N.,
McManus John B.,
Magan John J.,
Smith Christopher M.,
Duesberg Georg S.,
Kaminer Ido,
Wang Jun,
Blau Werner J.
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201902728
Subject(s) - ultrashort pulse , photonics , materials science , relaxation (psychology) , optoelectronics , band gap , semiconductor , renormalization , laser , absorption (acoustics) , condensed matter physics , optics , physics , psychology , social psychology , quantum mechanics , composite material
Carrier interactions in 2D nanostructures are of central importance not only in condensed‐matter physics but also for a wide range of optoelectronic and photonic applications. Here, new insights into the behavior of photoinduced carriers in layered platinum diselenide (PtSe 2 ) through ultrafast time‐resolved pump–probe and nonlinear optical measurements are presented. The measurements reveal the temporal evolution of carrier relaxation, chemical potential and bandgap renormalization in PtSe 2 . These results imply that few‐layer PtSe 2 has a semiconductor‐like carrier relaxation instead of a metal‐like one. The relaxation follows a triple‐exponential decay process and exhibits thickness‐dependent relaxation times. This occurs along with a band‐filling effect, which can be controlled based on the number of layers and may be applied in saturable absorption for generating ultrafast laser pulses. The findings may provide means to study many‐body physics in 2D materials as well as potentially leading to applications in the field of optoelectronics and ultrafast photonics.