Auger Effect Seen in the Porous Silicon Fast Luminescent Band

1998 ◽  
Vol 536 ◽  
Author(s):  
R. M'ghaïeth ◽  
I. Mihalcescu ◽  
H. Maâref ◽  
J. C. Vial

AbstractTime resolved photoluminescence (PL) measurements are performed on oxidized and fresh porous silicon at room temperature. Comparing the evolution of the nanosecond time delayed PL in both cases, a new feature of the PL spectra is identified: the fast-red band, present as well in fresh or aged samples. The nonlinear excitation intensity dependence of this component is described by a simple model where, the Auger effect inside isolated silicon nanocrystallites plays the dominant role.

Author(s):  
Д.В. Юрасов ◽  
Н.А. Байдакова ◽  
А.Н. Яблонский ◽  
А.В. Новиков

Light-emitting properties of Ge-on-Si(001) layers doped by Sb were studied by stationary and time-resolved photoluminescence (PL) at room temperature. It was obtained that the PL intensity of n-Ge/Si(001) structures is maximized when the doping level is close to the equilibrium solubility of Sb in Ge (~1019 cm-3) which is in accordance with the previously published data. Time-resolved studies of the direct-related PL signal have shown that both the donor density and the growth conditions of doped layer, in particular, the growth temperature influence the PL kinetics. It was obtained that the increase of doping level leads to the decrease of the characteristic carrier lifetime. Moreover, usage of low growth temperatures which is needed to form the doped n-Ge layers also results in shortening of the carrier lifetime as compared with Ge layers grown at high temperatures. It was found that rapid thermal anneal at proper conditions could partially compensate the above mentioned detrimental effects and lead to the increase of both the PL intensity and carrier lifetime.


2016 ◽  
Vol 70 (12) ◽  
pp. 1974-1980 ◽  
Author(s):  
Justin M. Reynard ◽  
Nathan S. Van Gorder ◽  
Caley A. Richardson ◽  
Richie D. Eriacho ◽  
Frank V. Bright

We report new instrumentation for rapidly and reliably measuring the temperature-dependent photoluminescence response from porous silicon as a function of analyte vapor concentration. The new system maintains the porous silicon under inert conditions and it allows on-the-fly steady-state and time-resolved photoluminescence intensity and hyper-spectral measurements between 293 K and 450 K. The new system yields reliable data at least 100-fold faster in comparison to previous instrument platforms.


1992 ◽  
Vol 283 ◽  
Author(s):  
V. Petrova-Koch ◽  
T. Muschik ◽  
D. I. Kovalev ◽  
F. Koch ◽  
V. Lehmann

ABSTRACTTime-resolved studies of the visible photoluminescence in porous silicon with three different coverages of the internal surface are reported. We use aged, naturally oxidized porous Si (oxihydride), rapid thermal processed material (oxide) and samples stored in HF (pure hydride). A new, fast luminescence band in the blue-green spectral range and with response time less than 100 ns is observed at room temperature in each of the samples, although with different intensities. The observations prove that this is not an oxide-defect luminescence. We speculate on mechanisms for the origin of the fast luminescence in nanometer-size crystallites of Si.


1997 ◽  
Vol 71 (1) ◽  
pp. 13-20 ◽  
Author(s):  
X. Wu ◽  
R. White ◽  
U. Hömmerich ◽  
F. Namavar ◽  
A.M. Cremins-Costa

1997 ◽  
Vol 72-74 ◽  
pp. 347-349 ◽  
Author(s):  
J. Kudrna ◽  
P. Bartošek ◽  
F. Trojánek ◽  
I. Pelant ◽  
P. Malý

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3904
Author(s):  
Kaveendra Maduwantha ◽  
Shigeyuki Yamada ◽  
Kaveenga Rasika Koswattage ◽  
Tsutomu Konno ◽  
Takuya Hosokai

Room-temperature phosphorescent (RTP) materials have been attracting tremendous interest, owing to their unique material characteristics and potential applications for state-of-the-art optoelectronic devices. Recently, we reported the synthesis and fundamental photophysical properties of new RTP materials based on benzil, i.e., fluorinated monobenzil derivative and fluorinated and non-fluorinated bisbenzil derivative analogues [Yamada, S. et al., Beilstein J. Org. Chem. 2020, 16, 1154–1162.]. To deeply understand their RTP properties, we investigated the excited-state dynamics and photostability of the derivatives by means of time-resolved and steady-state photoluminescence spectroscopies. For these derivatives, clear RTP emissions with lifetimes on the microsecond timescale were identified. Among them, the monobenzil derivative was found to be the most efficient RTP material, showing both the longest lifetime and highest amplitude RTP emission. Time-resolved photoluminescence spectra, measured at 77 K, and density functional theory calculations revealed the existence of a second excited triplet state in the vicinity of the first excited singlet state for the monobenzil derivative, indicative of the presence of a fast intersystem crossing pathway. The correlation between the excited state dynamics, emission properties, and conformational flexibility of the three derivatives is discussed.


2006 ◽  
Vol 958 ◽  
Author(s):  
Takashi Suemasu ◽  
Cheng Li ◽  
Tsuyoshi Sunohara ◽  
Yuta Ugajin ◽  
Ken'ichi Kobayashi ◽  
...  

ABSTRACTWe have epitaxially grown Si/β-FeSi2/Si (SFS) structures with β-FeSi2 particles or β-FeSi2 continuous films on Si substrates by molecular beam epitaxy (MBE), and observed 1.6 μm electroluminescence (EL) at room temperature (RT). The EL intensity increases with increasing the number of β-FeSi2 layers. The origin of the luminescence was discussed using time-resolved photoluminescence (PL) measurements. It was found that the luminescence originated from two sources, one with a short decay time (τ∼10 ns) and the other with a long decay time (τ∼100 ns). The short decay time was due to carrier recombination in β-FeSi2, whereas the long decay time was due probably to a defect-related D1 line in Si.


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