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Showing 1 to 20 of 249 for “"excitons"”.
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Coherence in nanostructured excitons
… antennas. Sunlight absorption first creates excitons. Complex antenna architectures control the excitons, directing them to reaction centers for conversion to chemical energy. Recently, studies found that excitonic interactions play a significant role in controlling antennas' light harvesting …
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Excitons in the Thallous-Halides
Made available in DSpace on 2015-05-12T21:41:51Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 6915268.PDF: 3684493 bytes, checksum: 06229140999c50218d2efe9c65969a2a (MD5) Previous issue date: 1969
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Excitons in the thallous halides
A thin film fabrication technique resulting in a considerable reduction in strain has been developed and has facilitated the optical and magneto-optical experiments on the Thallous Halides. The strain reduction achieved has revealed optical spectra of exceptional sharpness, Previously undiscovered …
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Decoherence and Dephasing of Vibronic Excitons /
… excitations are described as quasiparticles excitons. Coupling to vibrational degrees of freedom is often a dominating factor in the description of the exciton dynamics, therefore the vibronic exciton theory has to be used. In this thesis, the significance of dephasing and decoherence of …
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Lifetimes of Excitons in Cuprous Oxide
Submitted by Meng Tao (mengtao2@illinois.edu) on 2012-10-19T19:15:39Z No. of bitstreams: 1 Jang_Joon.pdf: 10079899 bytes, checksum: 98598584fa2b6ebd1cc4d1b1b3954f26 (MD5)
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Core excitons in amorphous magnesium alloys
… are thought to be due to the formation of core excitons. Variation in the strength of the excitonic resonance is explained by a simple screening argument. Variation in the line shape of the threshold is described by a critical exponent, and appears to be continuous between compositions having …
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Relaxation kinetics of excitons in cuprous oxide
… s~udied semiconductor with long-lived, mobile excitons. The kinetic energy distribution of the excitons is reproduced in phonon-assisted luminescence spectra. When non-equilibrium excitons are produced by a laser pulse, nanosecond-time-resolved luminescence reveals the relaxation of their …
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Quantum-confined excitons in 2-dimensional materials
… semiconductor materials which can trap single-excitons. The single excitons recombine radiatively to emit single-photons. Single-photon sources are a crucial requirement for many quantum information technology (QIT) applications such as quantum cryptography and quantum communication. The QDs …
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Terahertz driven intraband dynamics of excitons in nanorods
… CdSe nanorods to determine the dynamics of excitons generated via a short optical pulse. We calculate the energies and wavefunctions for the excitons within the envelope function approximation in the low density limit where there is at most one exciton per nanorod. The linear Terahertz …
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Local excitons in insulators and impurity doped metals
The local exciton spectra of some alkali-halide insulators and impurity doped lithium metal are calculated using atomic clusters to simulate the bulk solid. The calculations are ab initio and use unrestricted Hartree-Fock and second order many body perturbation techniques. Accurate results are …
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Bose-Einstein condensation of excitons in cuprous oxide
Free excitons provide the only experimental system other than helium in which the behavior of particles with mass is known to follow Bose-Einstein statistics. I present experimental observations of the kinetic energy distribution of excitons in the direct-gap semiconductor Cu$\sb2$O, both the …
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Luminescent Harnessing of 2D Transition Metal Dichalcogenide Excitons
… quantum confined nature produces tightly bound excitons that exhibit intriguing many-body phenomena. 2D excitons may be transferred to other emissive materials in a heterostructure system. This has applications in e.g., photon harvesting with luminescent solar concentrators (LSCs). Newly …
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Bose-Einstein condensation of excitons in uniaxially stressed Cu2O
Excitons in Cu20 have been demonstrated to be a nearly ideal gas of bosons, providing a unique system for studying Bose-Einstein statistics and Bose-Einstein Condensation of an ideal gas in the laboratory. In this study, I have applied uniaxial stress to optimize the conditions for a Bose-Einstein …
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Excitons in cuprous oxide: high mobilities and strain confinement
… of the spectral and spatial properties of excitons in the semiconductor cuprous oxide (CU0) at 2liquid helium temperatures. The lowest lying member of the yellow exciton series, the paraexciton, is the main focus of these studies. The technique cf time-resolved luminescence imaging was used …
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Spin-sensitive probes of triplet excitons in organic semiconductors
… the spin interactions of spin-1 triplet excitons formed by singlet fission. Singlet fission produces two triplet excitons from one light-induced singlet state and holds promise to enable solar energy generation beyond traditional efficiency limits. As the lifetime of triplet pairs depends …
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Optical and Spin Properties of Defect-Bound Excitons in Semiconductors
… of spontaneous emission from multi-carrier bound excitons. We apply this theory to the neutral-acceptor bound exciton, finding three distinct radiative lifetimes. Next, we utilize our knowledge of bound-exciton transitions to measure the spin lifetime of donor-bound electrons. These measurements …
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Interaction of Excitons and Impurity Atoms With Phonons in Germanium
Made available in DSpace on 2015-05-12T17:11:42Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 0004457.PDF: 1897859 bytes, checksum: 03fa2872cd019a618523c174b10f69d8 (MD5) Previous issue date: 1952
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Electric field effects on optical absorption by excitons in semiconductors
… states. The calculation is performed for Wannier excitons using the effective~mass approximation at both the Mo and M3 type edges. In comparison with single-particle theory, the inclusion of the electron-hole interaction increases the oscillator strengths at the Mo edge and at the same time …
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