Defect-assisted photoluminescence intensity enhancement in poly(p-phenylene vinylene) films probed by time-resolved photoluminescence

2003 ◽  
Vol 68 (3) ◽  
Author(s):  
M. Anni ◽  
G. Gigli ◽  
R. Cingolani ◽  
Y. Galvão Gobato ◽  
A. Vercik ◽  
...  
Keyword(s):  
Phenylene Vinylene ◽  
Photoluminescence Intensity ◽  
Time Resolved ◽  
Intensity Enhancement ◽  
Time Resolved Photoluminescence

Instrumentation for Reliably Determining Porous Silicon Photoluminescence Responses to Gaseous Analyte Vapors

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
Keyword(s):  
Porous Silicon ◽  
Vapor Concentration ◽  
Photoluminescence Intensity ◽  
Spectral Measurements ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Hyper Spectral ◽  
New Instrumentation ◽  
Time Resolved Photoluminescence ◽  
New System

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.

scholarly journals Study Study on photoluminescence properties of porous GaP material

2018 ◽  
Vol 34 (1) ◽  
Author(s):  
Pham Thi Thuy ◽  
Bui Xuan Vuong
Keyword(s):  
Solid State ◽  
Electrochemical Etching ◽  
Green Emission ◽  
Functional Materials ◽  
Bulk Sample ◽  
Electrochemical Anodization ◽  
Photoluminescence Intensity ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

This paper reports on the photoluminescence of porous GaPprepared by electrochemical anodization of (111)-oriented bulk material.Porous and bulk GaP exhibits green and red photoluminescence, respectively when excited by the 355-nm laser. The photoluminescence intensity of porous GaP is much stronger than that of the bulk sample. Temperature-dependent time-resolved photoluminescence shows that the green emission gradually decreases when the temperature increases and the photoluminescence full width at haft maximum (FWHM) slightly narrow with decreasing temperature. These results assigned to the contribution of lattice vibrations. Raman scattering measurement is carried out to confirm the size decreasing of the porous GaP material. Keywords PorousGaP, photoluminescence, time-resolved photoluminescence, electrochemical etching References 1. L. T. Canham, Appl. Phys.Lett. 57, 1046 (1990).2. K. Grigoras, Jpn. J. Appl. Phys. 39, 378 (2000)3. H. Koyama, J. Appl. Electrochem. 36, 999 (2006)4. H. A. Hadi, International Letters of Chemistry, Physics and Astronomy, 17(2), 142-152 (2014).5. S. Setzu, P. Ferrand, and R. Romestain, Mater.Sci. Eng, 34, 69-70 (2000).6. S. E. Letant and M. J. Sailor, Adv. Mater, 355, 12 (2000).7. M. T. Kelly, J. K. M. Chun, and A. B. Bocarsly, Nature, 382, 214 (1996).8. G. Di Francia, V. La Ferrara, L. Quercia, and G. Faglia, J. Porous Mater, 7, 287 (2000).9. J. Drott, K. Lindstrom, L. Rosengren, and T. Laurell, J. Micromech. Microeng, 7, 14 (1997).10. B. P. Azeredo, Y. W. Lin, A. Avagyan, M. Sivaguru, K. Hsu, P. Ferreira, Advanced Functional Materials, 26, 2929-2939 (2016).11. A. Anedda, A. Serpi, V. A. Karavanskii, I. M. Tiginyanu, and V. M. Ichizli, Appl. Phys.Lett, 67, 3316 (1995).12. A. I. Belogorokhov, V. A. Karavanskii, A. N. Obraztsov and V. Yu. Timoshenko, JETP Lett. 60, 274 (1994).13. K. Tomioka, S. Adachi, J. App. Phys, 98, 073511 (2005).14. M. A. Stevens-Kalceff, I. M. Tiginyanu, S. Langa, H. Foll and H. L. Hartnagel, J. App. Phys, 89,2560 (2001).15. A. V. Zoteev, P. K. Kashkarov, A. N. Obraztsov and V. Y. Timoshenko, Semiconductors, 30, 775 (1996).16. A. A. Lebedev, V. Y. Rud and Y. V. Rud, Tech. Phys. Lett, 22, 754 (1996).17. H. Richter, Z. P. Wang, and L. Ley, Solid State Commum, 39, 625 (1981).18. L. H. Campbell and P. M.Fauchet, Solid State Commum, 58, 739 (1986).19. V. V. Ursaki, N. N. Syrbu, S. Albu, V. V. Zalamai, I. M. Tiginyanu, and R. W. Boyd, Semicond. Sci. Technl, 20, 745- 748 (2005)20. R. W. Tjerkstra, Electrochemical and Solid-State Letters,9 (5), C81-C84 (2006)

scholarly journals Time Resolved Optical Studies of InGaN Layers Grown on LGO

2002 ◽  
Vol 743 ◽  
Author(s):  
Maurice Cheung ◽  
Gon Namkoong ◽  
Madalina Furis ◽  
Fei Chen ◽  
Alexander. N. Cartwright ◽  
...  
Keyword(s):  
Structural Quality ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
Time Resolved ◽  
Lattice Match ◽  
Spatially Resolved ◽  
Recombination Processes ◽  
Time Resolved Photoluminescence ◽  
Intensity Decay

ABSTRACTRadiative recombination processes in bulk InGaN grown by molecular beam epitaxy (MBE) on lithium gallate (LGO or LiGaO2) substrates were investigated using microscopic PL and time-resolved photoluminescence (TRPL). The improved structural quality resulting from a better lattice match of the LGO substrate to III-V nitride materials simplifies these investigations because well-defined composition phases can be analyzed for both homogeneous and phased separated InGaN samples. Epilayers of InGaN intentionally grown with and without indium segregation were studied. X-ray diffraction measurements showed that the homogeneous epilayer was high quality In0.208Ga0.702N and the segregated epilayer exhibited peaks corresponding to both In0.289Ga0.711N and In0.443Ga0.557N indicating the presence of higher In concentration regions in this sample. Spatially resolved photoluminescence spectra confirm the existence of these regions. The photoluminescence intensity decay is non-exponential for both samples and a stretched exponential fit to the decay data confirms the existence of local potential fluctuations in which carriers are localized before recombination.

scholarly journals Investigation on photoluminescence quenching of CdSe/ZnS quantum dots by organic charge transporting materials

2015 ◽  
Vol 33 (4) ◽  
pp. 709-713 ◽  
Author(s):  
Qu Yuqiu ◽  
Zhang Liuyang ◽  
An Limin ◽  
Wei Hong
Keyword(s):  
Quantum Dots ◽  
Oxidation Potential ◽  
Core Shell ◽  
Photoluminescence Intensity ◽  
Dynamic Quenching ◽  
Photoluminescence Quenching ◽  
Time Resolved ◽  
Quenching Efficiency ◽  
Hole Transporting ◽  
Time Resolved Photoluminescence

AbstractThe effect of different organic charge transporting materials on the photoluminescence of CdSe/ZnS core/shell quantum dots has been studied by means of steady-state and time-resolved photoluminescence spectroscopy. With an increase in concentration of the organic charge transporting material in the quantum dots solutions, the photoluminescence intensity of CdSe/ZnS quantum dots was quenched greatly and the fluorescence lifetime was shortened gradually. The quenching efficiency of CdSe/ZnS core/shell quantum dots decreased with increasing the oxidation potential of organic charge transporting materials. Based on the analysis, two pathways in the photoluminescence quenching process have been defined: static quenching and dynamic quenching. The dynamic quenching is correlated with hole transporting from quantum dots to the charge transporting materials.

Aggregate Formation in Pyridine-Based Polymers

1995 ◽  
Vol 413 ◽  
Author(s):  
J. W. Blatchford ◽  
S. W. Jessen ◽  
L. B. Lin ◽  
T. L. Gustafson ◽  
A. J. Epsteint ◽  
...  
Keyword(s):  
Thick Film ◽  
Stokes Shift ◽  
Spectroscopic Properties ◽  
Phenylene Vinylene ◽  
Aggregate Formation ◽  
Photoinduced Absorption ◽  
Time Resolved ◽  
Vibronic Structure ◽  
Time Resolved Photoluminescence ◽  
Versus Solution

ABSTRACTThe spectroscopic properties of the pyridine-based polymer poly(p-pyridyl vinylene p-phenylene vinylene) (PPyVPV) are examined. The emission of PPyVPV in solution has small intrinsic Stokes shift with some vibronic structure. In contrast, emission from thick film samples is featureless, with a strong redshift of ˜0.5 eV versus solution. We attribute these observations to the formation of aggregate states in film samples. Time-resolved photoluminescence measurements are in accord with the diffusion of excitons to the aggregate sites. Photoinduced absorption also originates from excitons in aggregate states.

Photoinduced photoluminescence intensity enhancement in poly(p-phenylene vinylene) films

2002 ◽  
Vol 81 (5) ◽  
pp. 942-944 ◽  
Author(s):  
Y. Galvão Gobato ◽  
A. Marletta ◽  
R. M. Faria ◽  
F. E. G. Guimarães ◽  
J. M. de Souza ◽  
...  
Keyword(s):  
Phenylene Vinylene ◽  
Photoluminescence Intensity ◽  
Intensity Enhancement

Investigation of Chemical Adsorbate Effects on Blue and Red Emitting Porous Silicon Samples

1994 ◽  
Vol 358 ◽  
Author(s):  
Julie M. Rehm ◽  
George L. McLendon ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet
Keyword(s):  
Steady State ◽  
Porous Silicon ◽  
Surface Passivation ◽  
Chemical Exposure ◽  
Nonradiative Recombination ◽  
Photoluminescence Intensity ◽  
Time Resolved ◽  
Optical Effects ◽  
Solvent Molecules ◽  
Time Resolved Photoluminescence

ABSTRACTWe have investigated the sensitivity of blue (PLmax = 480 nm) and red (PLmax = 660 nm) emitting porous silicon samples to various chemical adsorbates. Steady-state and time-resolved photoluminescence measurements and FTIR spectroscopy were employed to characterize the photophysical and optical effects induced by chemical exposure. The red samples, which are hydrogen terminated, exhibit quenching and recovery of photoluminescence intensity and broadening of the Si-Hx stretch bands upon exposure to liquid methanol. This behavior is attributed to the ability of the Si-Hx specie on the surface of the PSI to interact with the solvent molecules which temporarily traps the electrons and causes PL loss and Si-Hx broadening. The blue samples, which are oxygen terminated, display similar sensitivity to methanol. This sensitivity is attributed to the solvent's ability to change the surface passivation and thereby introduce competitive radiative and nonradiative recombination channels. The origin of the blue PL is discussed.

Photoexcitation Dynamics In Polymeric Heterostructures

1995 ◽  
Vol 413 ◽  
Author(s):  
G. Bongiovanni ◽  
S. Destri ◽  
A. Mura ◽  
A. Piaggi ◽  
R Tubino
Keyword(s):  
Density Of States ◽  
Exponential Decay ◽  
Stokes Shift ◽  
Photoluminescence Intensity ◽  
Nearest Neighbour ◽  
Time Resolved ◽  
Thermally Activated ◽  
Spectral Relaxation ◽  
Site Selective ◽  
Time Resolved Photoluminescence

ABSTRACTWe investigate the dynamics of photoexcitations in thiophene-based copolymers by site-selective and time-resolved photoluminescence spectroscopies. We attribute the large Stokes-shift observed between the absorption and luminescence peaks to spectral relaxation of excitons within an inhomogeneously broadened density of states. The non exponential decay of the photoluminescence intensity is explained through the interplay between spectral diffusion, thermally activated jumps and slow transfer to non nearest neighbour sites.

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