Subnanosecond transient studies of intrinsic and extrinsic luminescence in CdSe

1985 ◽  
Vol 63 (9) ◽  
pp. 1205-1211 ◽  
Author(s):  
T. Steiner ◽  
M. L. W. Thewalt
Keyword(s):  
Free Exciton ◽  
Exciton Luminescence ◽  
Time Resolved ◽  
Transient Behaviour ◽  
Doublet Structure ◽  
Donor And Acceptor ◽  
Optic Phonon ◽  
Longitudinal Optic ◽  
Low Levels ◽  
Longitudinal Optic Phonon

The photoluminescence spectrum and transient behaviour of free and bound excitons in CdSe have been studied with both resonant and above band-gap excitation. The free- and bound-exciton lifetimes were found to be excitation-intensity dependent even at very low levels. In all cases, the free-exciton luminescence decayed more rapidly than that of the bound excitons. A comparison of the no-phonon and longitudinal-optic-phonon replicas of the free-exciton luminescence indicates that the observed doublet structure of the no-phonon spectrum arises from the two polariton branches. Resonant excitation of the donor and acceptor bound excitons revealed two-electron and two-hole replicas, respectively. We believe these to be the first reported two-hole transitions in CdSe. The initial rapid cooling of the free-exciton gas could be observed in a series of time-resolved spectra.

Observation of longitudinal-optic-phonon-plasmon-coupled mode in n-type AlGaN alloy films

2011 ◽  
Vol 99 (25) ◽  
pp. 251904 ◽  
Author(s):  
Jung Gon Kim ◽  
Atsuhito Kimura ◽  
Yasuhito Kamei ◽  
Noriyuki Hasuike ◽  
Hiroshi Harima ◽  
...  
Keyword(s):  
Alloy Films ◽  
Coupled Mode ◽  
Optic Phonon ◽  
Longitudinal Optic ◽  
Longitudinal Optic Phonon

Time-resolved study of free exciton luminescence in KI and RbI

1998 ◽  
Vol 105 (11) ◽  
pp. 681-684 ◽  
Author(s):  
Toru Tsujibayashi ◽  
Koichi Toyoda ◽  
Tetsusuke Hayashi
Keyword(s):  
Free Exciton ◽  
Exciton Luminescence ◽  
Time Resolved

Coupled longitudinal optic phonon-plasmon modes in p-type GaN

1998 ◽  
Vol 106 (8) ◽  
pp. 491-494 ◽  
Author(s):  
F. Demangeot ◽  
J. Frandon ◽  
M.A. Renucci ◽  
N. Grandjean ◽  
B. Beaumont ◽  
...  
Keyword(s):  
Optic Phonon ◽  
Longitudinal Optic ◽  
Longitudinal Optic Phonon ◽  
P Type ◽  
Plasmon Modes

PHOTON YIELD FROM SOLID KRYPTON AND XENON AT THE EDGE OF EXCITON ABSORPTION

2002 ◽  
Vol 09 (01) ◽  
pp. 45-49 ◽  
Author(s):  
A. N. OGURTSOV ◽  
E. V. SAVCHENKO ◽  
E. GMINDER ◽  
S. VIELHAUER ◽  
G. ZIMMERER
Keyword(s):  
Synchrotron Radiation ◽  
Free Exciton ◽  
Photon Absorption ◽  
Exciton Luminescence ◽  
Photon Yield ◽  
Exciton Absorption ◽  
Excitation Spectra ◽  
Time Resolved ◽  
Solid Krypton ◽  
First Time

The spectra of photon yield from solid Xe and Kr were measured in the energy range of absorption of Γ(3/2) n = 1 excitons. Using combination of time-resolved spectroscopy with selective photoexcitation by synchrotron radiation, the creation of free excitons was experimentally separated from direct population of molecular emitting centers. For the first time the threshold of photon absorption by molecular trapped centers is observed in excitation spectra of free exciton luminescence.

Microraman Characterization Of Microdefects In Bulk Sic

1997 ◽  
Vol 483 ◽  
Author(s):  
E. Martín ◽  
M. Chafai ◽  
J. Jiménez
Keyword(s):  
Donor Concentration ◽  
Disorder Effects ◽  
Crystal Matrix ◽  
Local Fluctuations ◽  
Optic Phonon ◽  
Raman Modes ◽  
Longitudinal Optic ◽  
Longitudinal Optic Phonon ◽  
Microraman Spectroscopy

AbstractMicroRaman spectroscopy is used for characterizing defects in large SiC crystals with micrometer spatial resolution. The ability to identify microscopic inclusions of polytypes different than the crystal matrix is demonstrated; silicon and carbon inclusions and disorder effects are found in micropipes. A study of the Longitudinal Optic Phonon Plasmon Coupled (LOPC) Raman modes allowed to obtain local fluctuations of the net donor concentration, ND-NA, and the electron mobility around defects, which allowed impurity gettering effects to be observed.

Exciton Lifetimes in GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
J.P. Bergman ◽  
C. Harris ◽  
B. Monemar ◽  
H. Amano ◽  
I. Akasaki
Keyword(s):  
Decay Time ◽  
Low Temperatures ◽  
Radiative Recombination ◽  
Radiative Lifetime ◽  
Free Exciton ◽  
Time Resolved ◽  
A Value ◽  
Donor And Acceptor ◽  
Exciton Recombination ◽  
Time Resolved Photoluminescence

ABSTRACTWe have performed time resolved photoluminescence measurements of the exciton recombination in different GaN samples at low temperatures. In epitaxial layers the decay time of the free exciton is typically faster than 100 ps. This is due to a dominating non-radiative recombination process. In thick bulk samples we have resolved and measured the decay time of the free exciton with a value of about 200 ps. We believe that this value is close to the radiative lifetime for free excitons in GaN. We have also shown that excitation transfer occurs between free and bound exciton states. We have furthermore measured the decay of the donor and acceptor bound excitons, and obtained values of the decay time of 250 ps and 1200 ps, respectively.

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