Ultrafast Nonlinear Excitation Dynamics of Black Phosphorus Nanosheets from Visible to Mid-Infrared.
The recent progress on black phosphorus makes it a promising candidate material for broadband nanophotonic devices, especially operating in the mid-infrared spectral region. Here, the excited carrier dynamics and nonlinear optical response of unoxidized black phosphorus nanosheets and their wavelength dependence were systematically studied from 800 nm to 2.1 μm. The wavelength-dependent relaxation times of black phosphorus nanosheets are determined to be 360 fs to 1.36 ps with photon energies from 1.55 to 0.61 eV. In a comparative study with graphene, we found that black phosphorus has a faster carrier relaxation in near- and mid-infrared region. With regard to nonlinear optical absorption, the response of black phosphorus significantly increases from near- to mid-infrared, and black phosphorus is also confirmed to be better as saturable absorber to MoS2 in infrared region.
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Kangpeng
K
Wang
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Beata M
BM
Szydłowska
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Gaozhong
G
Wang
Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Shanghai 201800, China.
Xiaoyan
X
Zhang
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Jing Jing
JJ
Wang
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
John J
JJ
Magan
Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Shanghai 201800, China.
Long
L
Zhang
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Jonathan N
JN
Coleman
Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Shanghai 201800, China.|State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Shanghai 201800, China.
Jun
J
Wang
School of Physics and CRANN, Trinity College Dublin , Dublin 2, Ireland.
Werner J
WJ
Blau
2D nanomaterials; black phosphorus; nonlinear optics; pump−probe; saturable absorption; ultrafast spectroscopy; z-scan