Time-resolved photoluminescence in CdIn2S4

1987 ◽  
Vol 65 (3) ◽  
pp. 204-207 ◽  
Author(s):  
S. Charbonneau ◽  
E. Fortin ◽  
J. Beauvais
Keyword(s):  
Single Crystals ◽  
Free Electron ◽  
Continuous Wave ◽  
Time Window ◽  
Photoluminescence Spectra ◽  
Time Resolved ◽  
Spectral Bands ◽  
Window Technique ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence

Photoluminescence spectra of CdIn2S4 single crystals at 1.8 K under both continuous-wave (CW) and pulsed excitation were obtained. In the latter case, a variable time-window technique was used to observe the time evolution of the spectra between 0 and 100 μs. In contrast to previous studies, four spectral bands were observed under both CW and pulsed, intrinsic or extrinsic excitation. In particular, two bands previously unobserved under extrinsic excitation were detected at 1.35 and 1.68 eV, and have been attributed to donor–acceptor pairs and free-electron to acceptor transitions respectively.

Time-Resolved Photoluminescence Spectra in Single Crystals of CuAlS2:Mn

1991 ◽  
Vol 30 (Part 1, No. 2) ◽  
pp. 307-313 ◽  
Author(s):  
Katsuaki Sato ◽  
Koki Ishii ◽  
Kunio Watanabe ◽  
Kensei Ohe
Keyword(s):  
Single Crystals ◽  
Photoluminescence Spectra ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

scholarly journals Two - Color Mid-Infrared Spectroscopy of Isoelectronic Centers in Silicon

2003 ◽  
Vol 770 ◽  
Author(s):  
N.Q. Vinh ◽  
T. Gregorkiewicz
Keyword(s):  
Excited States ◽  
Free Electron ◽  
Free Electron Laser ◽  
Materials Science ◽  
Time Resolved ◽  
Mid Infrared ◽  
Semiconductor Physics ◽  
Open Questions ◽  
Time Resolved Photoluminescence ◽  
Tunable Source

AbstractOne of the open questions in semiconductor physics is the origin of the small splittings of the excited states of bound excitons in silicon. A free electron laser as a tunable source of the mid-infrared radiation (MIR) can be used to investigate such splittings of the excited states of optical centers created by transition metal dopants in silicon. In the current study, the photoluminescence from silver and copper doped silicon is investigated by two color spectroscopy in the visible and the MIR. It is shown the PL due recombination of exciton bound to Ag and Cu is quenched upon application of the MIR beam. The time-resolved photoluminescence measurements and the quenching effects of these bands are presented. By scanning the wavelength of the free-electron laser ionization spectra of relevant traps involved in photoluminescence are obtained. The formation and dissociation of the bound excitons, and the small splittings of the effective-mass excited states are discussed. The applied experimental method allows correlation of DLTS data on trapping centers to specific channels of radiative recombination. It can be applied for spectroscopic analysis in materials science of semicondutors.

scholarly journals Defect Characterization in ZnGeP2 by Time -Resolved Photoluminescence

1996 ◽  
Vol 450 ◽  
Author(s):  
N. Dietz ◽  
W. Busse ◽  
H. E. Gumlich ◽  
W. Ruderman ◽  
I. Tsveybak ◽  
...  
Keyword(s):  
Energy Range ◽  
Infrared Emission ◽  
Luminescence Spectra ◽  
Broad Emission Band ◽  
Wide Energy Range ◽  
Time Resolved ◽  
Broad Emission ◽  
Donor Acceptor ◽  
Donor States ◽  
Time Resolved Photoluminescence

AbstractSteady state and time-resolved photoluminescence (PL) investigations on ZnGeP2 crystals grown from the vapor phase by high pressure physical vapor transport (HPVT) and from the melt by gradient freezing (GF) are reported. The luminescence spectra reveal a broad infrared emission with peak position at 1.2 eV that exhibits features of classical donor-acceptor recombination. The hyperbolic decay characteristic over a wide energy range, investigated from 1.2 eV up to 1.5eV, suggest that this broad emission band is related to one energetic recombination center. Higher energetic luminescence structures at 1.6eV and 1.7eV were revealed after annealing of ZnGeP2 crystals in vacuum for a longer period of time. The emission decay behavior in this energy range is characterized by two hyperbolic time constants, viewed as the supercomposition of the decay from the broad emission center peaked at 1.2eV and additional donor-acceptor recombination emissions at 1.6eV and 1.7eV, respectively. ZnGeP2 crystals grown under Ge-deficient conditions by HPVT show an additional emission structure at 1.8 eV with sharp emission fine structures at 1.778 eV related to the presence of additional donor states.

scholarly journals Localized Surface Plasmon on 6H SiC with Ag Nanoparticles

2017 ◽  
Vol 897 ◽  
pp. 634-637
Author(s):  
Yi Wei ◽  
Ahmed Fadil ◽  
Hai Yan Ou
Keyword(s):  
Ag Nanoparticles ◽  
Internal Quantum Efficiency ◽  
Minority Carrier Lifetime ◽  
Fdtd Simulation ◽  
Localized Surface Plasmon ◽  
Ag Nanoparticle ◽  
Ag Nps ◽  
Time Resolved ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence

Silver (Ag) nanoparticles (NPs) were deposited on the surface of bulk Nitrogen-Boron co-doped 6H silicon carbide (SiC), and the Ag NPs were observed to induce localized surface plasmons (LSP) resonances on the SiC substrate, which was expected to improve the internal quantum efficiency (IQE) of the emissions of the donor-acceptor pairs of the SiC substrate. Room-temperature measurements of photoluminescence (PL), transmittance and time-resolved photoluminescence (TRPL) were applied to characterize the LSP resonances. Through the finite-difference time-domain (FDTD) simulation of the LSP resonance of an Ag nanoparticle on the SiC substrate, it is predicted that when the diameter of the cross section on the xy plane of the Ag nanoparticle is greater than 225 nm, the LSP starts to enhance the PL intensity. With implementation of a 3rd order exponential decay fitting model to the TRPL results, it is found that the average minority carrier lifetime of the SiC substrate decreased.

scholarly journals Time Resolved Photoluminescence of Cubic Mg Doped GaN

1999 ◽  
Vol 572 ◽  
Author(s):  
R. Seitz ◽  
C. Gaspar ◽  
T. Monteiro ◽  
E. Pereira ◽  
B. Schoettker ◽  
...  
Keyword(s):  
Blue Emission ◽  
Spectral Shift ◽  
Excitation Density ◽  
Acceptor Pair ◽  
Time Resolved ◽  
Deep Donor ◽  
Cubic Gan ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence ◽  
Mg Doped

ABSTRACTMg doped cubic GaN layers were studied by steady state and time resolved photoluminescence. The blue emission due to Mg doping can be decomposed in three bands. The decay curves and the spectral shift with time delays indicates donor-acceptor pair behaviour. This can be confirmed by excitation density dependent measurements. Furthermore temperature dependent analysis shows that the three emissions have one impurity in common. We propose that this is an acceptor level related to the Mg incorporation and the three deep donor levels are due to compensation effects.

Charge carrier dynamics in small-molecule- and polymer-based donor-acceptor blends

2014 ◽  
Vol 1733 ◽  
Author(s):  
Keshab Paudel ◽  
Brian Johnson ◽  
Mattson Thieme ◽  
John E. Anthony ◽  
Oksana Ostroverkhova
Keyword(s):  
Optical Absorption ◽  
Charge Carrier ◽  
High Performance ◽  
Continuous Wave ◽  
Carrier Dynamics ◽  
Bulk Heterojunctions ◽  
Time Resolved ◽  
Charge Carrier Dynamics ◽  
Donor Acceptor ◽  
532 Nm

ABSTRACTWe present a comparative study of optical absorption, photoluminescence (PL), and photoconductivity in bulk heterojunctions comprising a high performance functionalized anthradithiophene (ADT) derivative or the benchmark polymer P3HT as donor and functionalized pentacene (Pn) derivative or PCBM as acceptor. Of all D/A blends studied, the ADT/PCBM blend exhibited the highest charge photogeneration efficiencies under 532 nm excitation, leading to the highest amplitudes of time-resolved and continuous wave (cw) photocurrents. At nanosecond time scales after photoexcitation, both ADT-TES-F-based blends and the P3HT/Pn-TIPS-F8 blend exhibited photocurrents which were higher by a factor of 2-10, depending on the blend, than that in the P3HT/PCBM blend. However, cw photocurrents showed a different trend, with the ADT-TES-F/PCBM blend exhibiting only a factor of ∼2.5 higher photoresponse than that in the P3HT/PCBM blends, and the ADT-TES-F- and P3HT- based blends with Pn-TIPS-F8 showing a factor of ∼1.5-2.5 lower photoresponse than that in the P3HT/PCBM blend, due to other contributions, such as that of charge trap-limited transport, to cw photoresponse.

Time-resolved photoluminescence in band-edge region of hexagonal boron nitride single crystals

2008 ◽  
Vol 17 (4-5) ◽  
pp. 830-832 ◽  
Author(s):  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
Takashi Kuroda ◽  
Osamu Tsuda ◽  
Hisao Kanda
Keyword(s):  
Boron Nitride ◽  
Single Crystals ◽  
Hexagonal Boron Nitride ◽  
Band Edge ◽  
Edge Region ◽  
Time Resolved ◽  
Time Resolved Photoluminescence
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