Light Scattering From Polaritons And Plasmaritons In Cds Near Resonance

We have investigated light scattering from polaritons and plasmaritons in CdS near resonance. These results are compared with computer-calculated dispersion curves for these excitations. We find a good agreement between theory and experiments. Particular attention is given to interesting effects arising from birefringence and resonance. © 1971 The American Physical Society.3124238424

Resonant Raman Scattering From Polaritons In Znse

Raman scattering from polaritons was studied near resonance in ZnSe. Detailed dispersion curves were determined experimentally for different incident frequencies and compared with theoretical results. Measurements of linewidth and relative scattered intensities were also performed. The observed polariton dispersion curves showed a deviation from theory near the same frequencies for which line broadening occurred, indicating the necessity of including relaxation effects depending on polariton frequency. Structure in the polariton intensity as a function of frequency, not observed before, may also be related to damping. © 1975 The American Physical Society.11279880

Many-body And Hot-phonon Effects In The Radiative Emission Spectrum Of Cds Under High Excitation Intensities

We present here experimental results concerning the photoluminescence spectrum of CdS under high excitation intensities. With increasing excitation intensity the single emission band observed at 77 °K shows a peak displacement towards lower energies, and enhancement of its low-energy side as well as of its high-energy side. These effects increase with excitation intensity. We develop a complete model that can account for the above behavior and the emission band shape. The broadening is mainly due to nonequilibrium distribution of LO phonons, though contributions to the high-energy side from hot electrons is quite significant. Self-energy corrections account for the band reduction and consequently to the shift of the luminescence band peak towards lower energies. © 1975 The American Physical Society.1162213222

Radiative Spectra From Hot Photocarriers

Radiative recombination from non-equilibrium carriers in semiconductors is compared with single-particle scattering in GaAs. The Raman scattering data is obtained by two-photon absorption in bulk material whereas the photoluminescence spectra are obtained by regular one-photon absorption. The results are in close agreement with current theories.211177178Shah, Leite, (1969) Phys. Rev. Lett., 22, p. 1304Meneses, Jannuzzi, Leite, (1973) Solid State Comm., 13, p. 245Shah, (1974) Phys. Rev. B, 9, p. 562Shah, (1974) Phys. Rev. B, 10, p. 3697Shah, Leite, Scott, (1970) Solid State Comm., 8, p. 1089Mattos, Leite, (1973) Solid State Comm., 12, p. 465Mattos, Guimarães, Leite, (1973) Opt. Comm., 8, p. 73Turtelli, de Castro, Leite, (1975) Solid State Comm., 16, p. 96

Hot Electron And Hot Phonon Contributions To Radiative Emission Spectra In Cds At High Excitation Intensities

The dependence of excitation frequency of photoluminescence spectral shape of CdS at high excitation intensities allowed discrimination between hot phonon and hot electron contributions to the broadening of the emission band on one side and the broadening due to many body effects on the other. It was found that the shift towards lower energies of the emission peak is mainly due to induced high carrier density and that the broadening is related to the presence of high densities of optical phonons and hot carriers. © 1975.166763765Jannuzzi, Meneses, Leite, (1972) Solid State Commun., 10, p. 517Leite, Ripper, Guglielmi, (1964) Appl. Phys. Lett., 5, p. 188Meneses, Jannuzzi, Leite, Band gap reduction in CdS due to high density of photo-injected carriers (1972) Solid State Communications, 10, p. 517Shah, Leite, (1969) Phys. Rev. Lett., 22, p. 1304Meneses, Luzzi, (1973) Solid State Commun., 12, p. 447Shah, Leite, Scott, (1970) Solid State Commun., 8, p. 1089Mattos, Leite, (1973) Solid State Commun., 12, p. 465Mattos, Guimarães, Liete, (1973) Opt. Commun., 8, p. 73LUZZI R. and RAMOS J.G.P., Solid State Commun. (to be published)MENESES E.A. and LUZZI R. (to be published)MENESES E.A., JANNUZZI N., LUZZI R., RAMOS J.G.P. and LEITE R.C.C. (to be published)Shank, Dienes, Trozzolo, Myer, NEAR uv TO YELLOW TUNABLE LASER EMISSION FROM AN ORGANIC DYE (1970) Applied Physics Letters, 16, p. 10Shank, Dienes, Trozzolo, Myer, (1970) Appl. Phys. Lett., 16, p. 40

Band Gap Reduction In Cds Due To High Density Of Photo-injected Carriers

At high photoexcitation levels the intrinsic radiative emission band in CdS, displays strong distortions which increase with excitation intensity. The two main features are a shift towards lower energies and a broadening of the lower energy side of the emission band. These effects are attributed to the high density of injected carriers. © 1972.106517520Hwang, (1970) J. appl. Phys., 41, p. 2668. , See for instance, and references cited thereinBasov, Bogdankevich, Goncharov, Lavrushin, Sudzilowski, (1966) Dokl. Acad. Nauk SSSR, 168, p. 1283. , See for instance(1966) Soviet Phys. Dokl., 11, p. 522. , translated, and references cited thereinShah, Leite, (1969) Phys. Rev. Lett., 22, p. 1304Leite, Shah, Gorden, (1969) Phys. Rev. Lett., 23, p. 1332Nathan, Burns, (1964) Proc. Third Int. Symp. on Quantum Electronics, p. 1863. , Paris, Columbia, New Yor

Resonant Raman Scattering Of To(a1), To(e1) And E2 Optical Phonons In Gan

Resonant Raman Scattering by optical phonons in GaN was observed under conditions that permitted comparison with the 'bare exciton' theory. Excellent agreement was obtained. Results covered an energy range from ≈ 800 to 300 meV below the gap energy, which shows that even at such energies exciton effects are dominant for Raman scattering. © 1972.111013511353Leite, Porto, (1966) Phys. Rev. Lett., 17, p. 10Wright, (1969) Proc. of Int. Conf. on Light Scattering in Solids, , See for instance, Springer, New YorkBalkanski, (1971) Proc. of Int. Conf. on Light Scattering in Solids, , Flammarion, ParisBendow, Birman, Ganguly, Damen, Leite, Scott, (1970) Opt. Commun., 1, p. 267Lewis, Wadsack, Chang, (1971) Light Scattering in Solids, , M. Balkanski, Flammarion, ParisZigone, Beserman, Balkanski, (1971) Light Scatteting in Solids, , M. Balkanski, Flammarion, ParisMaruska, Tietjen, (1969) Appl. Phys. Lett., 15, p. 327Pankove, Berkeyheirer, Maruska, Wittke, (1970) Solid State Commun., 8, p. 1051Marchon, Jr., Barker, Dean, Zetterstron, Optical studies of the phonons and electrons in gallium nitride (1970) Solid State Communications, 8, p. 1227Leite, Damen, Scott, (1969) Light Scattering in Solids, , G.B. Wright, Springer, New YorkLoudon, The Raman effect in crystals (1964) Advances in Physics, 13, p. 423. , J. Phys. 26 1965 67

Photoexcited Hot Phonons And Phonon Lifetimes In Gaas

A study of optical lifetimes as determined from surface conditions is made through Raman lineshape analysis and non-equilibrium phonon distributions induced by energetic photoelectrons. Results indicate that first-order Raman scattered linewidths are lifetime determined and that phonon lifetimes depend upon surface conditions. Our observations also give strong support to the mechanism and analysis proposed earlier for hot phonon generation through photoelectron relaxation. © 1973.817375Damen, Leite, Shah, (1970) Proc. of the Xth International Conference on the Physics of Semiconductors, , S.P. Keller, U.S. Atomic Energy Commission, WashingtonShah, Leite, Scott, (1970) Solid State Commun., 8, p. 1089J.C.V. Mattos and R.C.C. Leite, Solid State Commun., to be publishe

Raman Scattering By The Upper Branch Polariton In Zno

The first observation of Raman scattering from the upper branch polariton in a semiconductor is reported. The significant reduction in collecting solid angle is the main cause that allows for this observation. The experimental polariton dispersion relation ω(K) can only be accounted for when dispersion is taken into consideration. © 1975.171113791380NS074444; NIH; National Institutes of Health; NS079585; NIH; National Institutes of Health; NS082957; NIH; National Institutes of Health; NS083007; NIH; National Institutes of HealthHenry, Hopfield, (1965) Phys. Rev. Lett., 15, p. 964Porto, Tell, Damen, (1966) Phys. Rev. Lett., 16, p. 450Scott, Light Scattering from Polaritons (1971) American Journal of Physics, 39, p. 1360. , See literature cited inClaus, Light scattering by optical phonons and polaritons in perfect crystals (1972) Physica Status Solidi (b), 506, p. 11Leite, Damen, Scott, (1969) Proc. Int. Conf. Light Scattering Spectra of Solids, p. 359. , NY, Springer-Verlag, NYNicola, Leite, (1975) Phys. Rev., 11 B, p. 798NICOLA J.H. & LEITE R.C.C. (to be published)Ushioda, McMullen, (1972) Solid State Commun., 11, p. 299Bond, Measurement of the Refractive Indices of Several Crystals (1965) Journal of Applied Physics, 36, p. 197