Photoluminescence and

Band gaps in semiconductors can be investigated by other optical methods, such as photoluminescence, cathodoluminescence, photoluminescence excitation spectroscopy, absorption, spectral ellipsometry, photocurrent spectroscopy, and resonant Raman spectroscopy. Photoluminescence and cathodoluminescence involve an emission process and hence can be used to evaluate only features near the fundamental band gap. The other methods are related to the absorption process or its derivative (resonant Raman scattering). Most of these methods require cryogenic temperatures. 

Numerous ternary systems are known for II-VI structures incorporating elements from other groups of the Periodic Table. One example is the Zn-Fe-S system Zn(II) and Fe(II) may substimte each other in chalcogenide structures as both are divalent and have similar radii. The cubic polymorphs of ZnS and FeS have almost identical lattice constant a = 5.3 A) and form solid solutions in the entire range of composition. The optical band gap of these alloys varies (rather anomalously) within the limits of the ZnS (3.6 eV) and FeS (0.95 eV) values. The properties of Zn Fei-xS are well suited for thin film heterojunction-based solar cells as well as for photoluminescent and electroluminescent devices. 

It was observed in other works that in sulfide electrolyte, decomposition of ZnSe was still obtained stable PECs could be constructed though from singlecrystal, n-type, Al-doped ZnSe electrodes and aqueous diselenide or ditelluride electrolytes [124]. Long-term experiments in these electrolytes were accompanied by little electrode weight loss, while relatively constant photocurrents and lack of surface damage were obtained, as well as competitive electrolyte oxidation. Photoluminescence and electroluminescence from the n-ZnSe Al electrodes were investigated. 

Strickert HH, Tong JR, EUis AB (1982) Luminescent photoelectrochemical cells. 6. Spatial aspects of the photoluminescence and electroluminescence of cadmium selenide electrodes. J Am Chem Soc 104 581-588... 

Ouyang J, Pan ERE, Bard AJ (1989) Semiconductor Electrodes, 62. Photoluminescence and electroluminescence from manganese-doped ZnS and CVD ZnS electrodes. J Electrochem Soc136 1033-1039... 

Becker WG, Bard AJ (1983) Photoluminescence and photoinduced oxygen adsorption of coUoidal zinc sulfide dispersions. J Phys Chem 87 4888 893... 

This chapter presents an overview of the synthesis, ensemble photoluminescence properties and blinking of single CdSe quantum dots. The stress is on (i) widely accepted methods of synthesis, (ii) the origin of photoluminescence and variations of photoluminescence as functions of surface-coating, surface-passivating molecules, chemical environment, and thermal- and photo-activations, and (iii) photolumines-... 

Figure 17.6 (A) Temporal evolution of photoluminescence and UV spectra (B) of CdSe quantum dots dispersed in CHCI3 [29], (C) The evolution curves of the photoluminescence peak intensity of quantum dot films on four kinds of SiOx substrates [34], Reprinted with permission from references [29] (A) and [34] (B) copyright [2003], American Chemical Society and copyright [2006], American Institute of Physics.

Moreno M, Aramburu JA, Barriuso MT (2003) Electronic Properties and Bonding in Transition Metal Complexes Influence of Pressure 106 127-152 Morita M, Buddhudu S, Rau D, Murakami S (2004) Photoluminescence and Excitation Energy Transfer of Rare Earth Ions in Nanoporous Xerogel and Sol-Gel SiC>2 Glasses 107 115-143... 

Recently, Gianotti et al. (96) reported photoluminescence and DRUV spectra of pure siliceous MCM-41 and Ti-MCM-41 containing Ti4+ species anchored to the inner walls of the siliceous MCM-41. They observed complex luminescence signals and concluded that these could be used for a clear distinction of the emission of tetrahedral Ti4+ ions from those of silica surface centers. 

FIGURE 1.10 Optical absorption, photoluminescence and electroluminescence (circle) of Covion SY film. 

MR Andersson, G Yu, and AJ Heeger, Photoluminescence and electroluminescence of films from soluble PPY-polymers, Synth. Met., 85 1275-1276, 1997. 

D.M. Johansson, M. Theander, G. Srdanov, G. Yu, O. Inganas, and M.R. Andersson, Influence of polymerization temperature on molecular weight, photoluminescence, and electroluminescence for a phenyl-substituted poly(p-phenylene vinylenes), Macromolecules, 34 3716-3719, 2001. 

T. Ahn, S. Song, and H. Shim, Highly photoluminescent and blue-green electroluminescent polymers new silyl- and alkoxy-substituted poly(p-phenylene vinylene) related copolymers containing carbazole or fluorene groups, Macromolecules, 33 6764-6771, 2000. 

M. Hohloch, J.L. Segura, S.E. Dottinger, D. Honhholz, E. Steinhuber, H. Spreitzer, and M. Hanack, Design, synthesis and study of photoluminescence and electroluminescence of new poly(2,6-naphthylene vinylene) derivatives, Synth. Met., 84 319-322, 1997. 

M. Ranger, D. Rondeau, and M. Leclerc, New well-defined poly(2,7-fluorene) derivatives photoluminescence and base doping, Macromolecules, 30 7686-7691, 1997. 

A Bolognesi, C Botta, and M Martinelli, Oriented poly(3-alkylthiophene) films absorption, photoluminescence and electroluminescence behaviour, Synth. Met., 121 1279-1280, 2001. 

GG Roberts, M McGinnity, WA Barlow, and PS Vincett, Electroluminescence, photoluminescence and electroabsorption of a lightly substituted anthracene Langmuir film, Solid State Commun., 32 683-686, 1979. 

The quantized nature of electronic energy levels due to size confinement is amplified in this term. They show characteristic absorption features and can be distinguished from each other from their absorption profiles [2], Quantum clusters typically exhibit strong photoluminescence and their wavelength of emission can be tuned from the near infra red (NIR) to ultra violet (UV) [1]. 

Gu Z, Bao Y-J, Zhang Y, Wang M, Shen Q-D (2006) Anionic water-soluble poly(phenyle-nevinylene) alternating copolymer high-efficiency photoluminescence and dual electroluminescence. Macromolecules 39 3125-3131... 

Levi N, Hantgan RR, Lively MO, Carroll DL, Prasad GL (2006) C60-Fullerenes Detection of intracellular photoluminescence and lack of cytotoxic effects. J. Nanobiotechnol. 4 14. 

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