Michael A. Stroscio

Advances in Semiconductor Lasers and Applications to Optoelectronics

This volume includes highlights of the theories underlying the essential phenomena occurring in novel semiconductor lasers as well as the principles of operation of selected heterostructure lasers. To understand scattering processes in heterostructure lasers and related optoelectronic devices, it is essential to consider the role of dimensional confinement of charge carriers as well as acoustical and optical phonons in quantum structures. Indeed, it is important to consider the confinement of both phonons and carriers in the design and modelling of novel semiconductor lasers such as the tunnel injection laser, quantum well intersubband lasers, and quantum dot lasers. The full exploitation of dimensional confinement leads to the capability of scattering time engineering in novel semiconductor lasers.

Quantum-based electronic devices and systems

Architectures for quantum-based systems - chemically self-assembled nanoelectronic computing networks, S. Bandhopadhyay et al quantum-dot cellular automata devices and architectures, W. Porod first generation quantum devices - two-dimensional electrons in field effect transistors, M.S. Shur and M. Dyakonov quantum wires and quantum dots - carbon nanotubes and nanotube-based nano devices, J.-P. Lu and J. Han scattering time engineering in quantum-based electronic devices, J.-P. Leburton room temperature silicon quantum devices, R. Tsu single electron devices - single electron devices, D.D. Smith some consequences of chaos for quantum devices, S. Washburn theory - Bloch electron dynamics in spatially homogenous electric fields, G.J. Iafrate et al Schrodinger equation Monte Carlo - bridging the gap from quantum to classical transport, L.F. Register recent developments on electron-phonon interactions in structures for quantum-based electronic and opto-electronic devices, M. Dutta et al.

Optical and electrical measurement of energy transfer between nanocrystalline quantum dots and photosystem I.

In the natural photosynthesis process, light harvesting complexes (LHCs) absorb light and pass excitation energy to photosystem I (PSI) and photosystem II (PSII). In this study, we have used nanocrystalline quantum dots (NQDs) as an artificial LHC by integrating them with PSI to extend their spectral range. We have performed photoluminescence (PL) and ultrafast time-resolved absorption measurements to investigate this process. Our PL experiments showed that emission from the NQDs is quenched, and the fluorescence from PSI is enhanced. Transient absorption and bleaching results can be explained by fluorescence resonance energy transfer (FRET) from the NQDs to the PSI. This nonradiative energy transfer occurs in ∼6 ps. Current-voltage (I-V) measurements on the composite NQD-PSI samples demonstrate a clear photoresponse.

Integrating and Tagging Biological Structures with Nanoscale Semiconductor Quantum dot Structures

This account has highlighted the recent progress in using semiconductor biotags based on their narrow, tunable and symmetric emission spectra as well as their temporal stability and resistance to photobleaching, especially as compared to fluorescent dyes. This progress has been possible as a result of key developments underlying the synthesis and functionalization of semiconductor nanocrystals. The advances in binding fluorescent semiconductor nanocrystals to biomolecules have facilitated the selective binding of these nanoscale fluorescent structures to specific subcellular structures. To go beyond using nanocrystals as biotags by integrating semiconductor nanocrystals directly with biological structures, it is necessary to further understand the physical properties of semiconductor nanocrystals in biological environments and in direct contact with biological structures. This review has highlighted several such interaction mechanisms, including the interaction of electrolytes with nanocrystals, the modification of the photoluminescence spectra of nanocrystals due to the environmentally-induced changes in the acoustic phonon spectra in nanocrystals, and the role of surface states on the observed intermittent blinking of quantum dots. To realize the possible uses of semiconductor nanocrystals as elements of coupled nanocrystal-biological-systems, it is necessary to study such interaction mechanisms in greater detail.

Surface-enhanced Raman spectroscopy study of single stranded DNA sequences on silver nanorod array

The spectral signatures of two samples of single stranded DNA were analyzed using Raman spectroscopy. One was a 15-base thymine sequence and the other was an aptamer containing thymine and guanine bases. A Surfaceenhanced Raman spectroscopy (SERS) substrate was used to enhance the signal to detectable levels. Many vibrational modes corresponding to bonds within DNA were detected.

Acoustic phonons in rectangular quantum wires: approximate compressional modes and the corresponding deformation potential interactions

The Hamiltonian describing the deformation potential interaction of confined acoustic phonons with carriers is derived by quantizing the appropriate, experimentally verified approximate compressional acoustic phonon modes in a rectangular quantum wire. The scattering rate due to the deformation potential interaction is calculated for a range of quantum wire dimensions.

Real-space transfer of photoexcited electrons in type-II superlattices via optical-phonon emission

The (Gamma) -X scattering rate of electrons in type-II superlattices by optical-phonon emission is calculated. The tight binding method for electronic band structure and the dielectric continuum model for phonons are used. The relative strength of scattering due to different phonon modes is examined for varying superlattice dimensions. The scattering rate is highest when the energy separation between the (Gamma) and X levels is smallest, and decreases quickly as the separation increases. It is found that the strongest scattering rate is due to the emission of AlAs confined modes. Changing of parity with layer thickness and its effect on scattering are discussed.

Phonons in Nanostructures by Michael A. Stroscio

Preface The first part: 1. Phonons in nanostructures 2. Phonons in bulk cubic crystals 3. Phonons in bulk wurtzite crystals 4. Raman properties of bulk phonons 5. Occupation number representation and general formulation of carrier-phonon scattering rates 6. Anharmonic coupling of phonons 7. Continuum models for phonons in bulk and dimensionally-confined semiconductors 8. Carrier-LO-phonon scattering 9. Carrier-acoustic-phonon scattering 10. Recent developments on electron-phonon interactions in structures in electronic and optoelectronic devices 11. Concluding considerations Appendices.

Phonons in Nanostructures: Frontmatter

Preface The first part: 1. Phonons in nanostructures 2. Phonons in bulk cubic crystals 3. Phonons in bulk wurtzite crystals 4. Raman properties of bulk phonons 5. Occupation number representation and general formulation of carrier-phonon scattering rates 6. Anharmonic coupling of phonons 7. Continuum models for phonons in bulk and dimensionally-confined semiconductors 8. Carrier-LO-phonon scattering 9. Carrier-acoustic-phonon scattering 10. Recent developments on electron-phonon interactions in structures in electronic and optoelectronic devices 11. Concluding considerations Appendices.

Phonons in Nanostructures: Index

Preface The first part: 1. Phonons in nanostructures 2. Phonons in bulk cubic crystals 3. Phonons in bulk wurtzite crystals 4. Raman properties of bulk phonons 5. Occupation number representation and general formulation of carrier-phonon scattering rates 6. Anharmonic coupling of phonons 7. Continuum models for phonons in bulk and dimensionally-confined semiconductors 8. Carrier-LO-phonon scattering 9. Carrier-acoustic-phonon scattering 10. Recent developments on electron-phonon interactions in structures in electronic and optoelectronic devices 11. Concluding considerations Appendices.