Improved light emission and suppression of exciton exciton annihilation rate in monolayer tungsten disulfide by laser irradiation (Conference Presentation)

2018 ◽  
Author(s):  
Yongjun Lee ◽  
Ganesh Ghimire ◽  
Youngbum Kim ◽  
Changwon Seo ◽  
Jeongyong Kim
Keyword(s):  
Laser Irradiation ◽  
Light Emission ◽  
Tungsten Disulfide ◽  
Annihilation Rate ◽  
Exciton Annihilation

scholarly journals Effect of Laser Irradiation on Emissivity of Flame-Generated Nanooxides

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2303
Author(s):  
Silvana De Iuliis ◽  
Roberto Dondè ◽  
Igor Altman
Keyword(s):  
Laser Irradiation ◽  
Light Emission ◽  
Energy Gap ◽  
Particle Temperature ◽  
Electron Excitation ◽  
Flame Spray ◽  
Energy Bands ◽  
Light Emitting ◽  
Spectral Behavior ◽  
The Difference

The application of pyrometry to retrieve particle temperature in particulate-generating flames strictly requires the knowledge of the spectral behavior of emissivity of light-emitting particles. Normally, this spectral behavior is considered time-independent. The current paper challenges this assumption and explains why the emissivity of oxide nanoparticles formed in flame can change with time. The suggested phenomenon is related to transitions of electrons between the valence and conduction energy bands in oxides that are wide-gap dielectrics. The emissivity change is particularly crucial for the interpretation of fast processes occurring during laser-induced experiments. In the present work, we compare the response of titania particles produced by a flame spray to the laser irradiation at two different excitation wavelengths. The difference in the temporal behavior of the corresponding light emission intensities is attributed to the different mechanisms of electron excitation during the laser pulse. Interband transitions that are possible only in the case of the laser photon energy exceeding the titania energy gap led to the increase of the electron density in the conduction band. Relaxation of those electrons back to the valence band is the origin of the observed emissivity drop after the UV laser irradiation.

White-light-emitting magnetite nanoparticle–polymer composites: photonic reactions of magnetic multi-granule nanoclusters as photothermal agents

Nanoscale ◽  
2016 ◽  
Vol 8 (39) ◽  
pp. 17136-17140 ◽  
Author(s):  
Yu Jin Kim ◽  
Bum Chul Park ◽  
June Park ◽  
Hee-Dae Kim ◽  
Nam Hoon Kim ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Laser Irradiation ◽  
White Light ◽  
Magnetite Nanoparticles ◽  
Light Emission ◽  
White Light Emission ◽  
Magnetite Nanoparticle ◽  
Light Emitting

Magnetite nanoparticles combined with polymers produce white-light emission under multiphoton laser irradiation.

Visible light emission from single layer Si nanodots fabricated by laser irradiation method

2006 ◽  
Vol 89 (16) ◽  
pp. 163107 ◽  
Author(s):  
Zhanhong Cen ◽  
Jun Xu ◽  
Yansong Liu ◽  
Wei Li ◽  
Ling Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Laser Irradiation ◽  
Light Emission ◽  
Single Layer ◽  
Visible Light Emission

Total and Radiative Triplet-Triplet Exciton-Annihilation Rate Constant in Pyrene Crystals

1973 ◽  
Vol 8 (12) ◽  
pp. 6038-6042 ◽  
Author(s):  
V. Ern ◽  
H. Bouchriha ◽  
M. Bisceglia ◽  
S. Arnold ◽  
M. Schott
Keyword(s):  
Rate Constant ◽  
Triplet Exciton ◽  
Annihilation Rate ◽  
Exciton Annihilation

Angle-dependent light emission from aligned multiwalled carbon nanotubes under CO2 laser irradiation

2007 ◽  
Vol 18 (7) ◽  
pp. 075710 ◽  
Author(s):  
Y Zhang ◽  
T Gong ◽  
W J Liu ◽  
J Q Wei ◽  
X F Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Laser Irradiation ◽  
Multiwalled Carbon Nanotubes ◽  
Co2 Laser ◽  
Light Emission ◽  
Multiwalled Carbon

scholarly journals Suppression of exciton-exciton annihilation in tungsten disulfide monolayers encapsulated by hexagonal boron nitrides

2017 ◽  
Vol 95 (24) ◽  
Author(s):  
Yusuke Hoshi ◽  
Takashi Kuroda ◽  
Mitsuhiro Okada ◽  
Rai Moriya ◽  
Satoru Masubuchi ◽  
...  
Keyword(s):  
Tungsten Disulfide ◽  
Boron Nitrides ◽  
Exciton Annihilation

Exciton fission and annihilation in crystalline tetracene

1977 ◽  
Vol 30 (11) ◽  
pp. 2353 ◽  
Author(s):  
GR Fleming ◽  
DP Millar ◽  
GC Morris ◽  
JM Morris ◽  
GW Robinson
Keyword(s):  
Room Temperature ◽  
Streak Camera ◽  
Annihilation Rate ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Singlet Exciton ◽  
Exciton Lifetime ◽  
Upper Limit ◽  
Exciton Annihilation ◽  
Hopping Model

The time-resolved fluorescence of tetracene crystals excited by a single 7-ps pulse of 530-nm light has been measured with a streak camera/OMA system. The singlet exciton lifetime was found to be 300�30 ps at 293 K. Singlet-singlet exciton annihilation was observed, and the rate constant found to be 5 x 10-9 cm3 s-1. In order to fit the observed decay curves, an upper limit of c. 1 x 10-9 cm3 s-1 must be set on the singlet-triplet exciton annihilation rate. The measured singlet-singlet exciton annihilation rate is consistent with a hopping model for singlet exciton motion at room temperature.

Sign in / Sign up

Export Citation Format

Share Document