Browsing by Keywords "Nanocrystals"
Now showing items 1-20 of 89
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Analysis of strain fields in silicon nanocrystals
(American Institute of Physics, 2009)Strain has a crucial effect on the optical and electronic properties of nanostructures. We calculate the atomistic strain distribution in silicon nanocrystals up to a diameter of 3.2 nm embedded in an amorphous silicon ... -
Bio-nanohybrids of quantum dots and photoproteins facilitating strong nonradiative energy transfer
(Royal Society of Chemistry, 2013-05-21)Utilization of light is crucial for the life cycle of many organisms. Also, many organisms can create light by utilizing chemical energy emerged from biochemical reactions. Being the most important structural units of the ... -
CdSe/ZnS core-shell nanocrystal based scintillators for enhanced detection in UV
(IEEE, 2006)In this work, we present a novel scintillator that incorporates CdSe/ZnS core-shell nanocrystals to utilize both their high quantum fluorescence efficiency in the visible and high optical absorption in the UV for the purpose ... -
Charge retention in quantized energy levels of nanocrystals
(Elsevier B.V., 2007)Understanding charging mechanisms and charge retention dynamics of nanocrystal (NC) memory devices is important in optimization of device design. Capacitance spectroscopy on PECVD grown germanium NCs embedded in a silicon ... -
Colloidal nanocrystals embedded in macrocrystals: methods and applications
(American Chemical Society, 2016)Colloidal semiconductor nanocrystals have gained substantial interest as spectrally tunable and bright fluorophores for color conversion and enrichment solids. However, they suffer from limitations in processing their ... -
Colloidal Nanocrystals Embedded in Macrocrystals: Robustness, Photostability, and Color Purity
(American Chemical Society, 2012-09-14)The incorporation of colloidal quantum dots (QDs) into ionic crystals of various salts (NaCl, KCl, KBr, etc.) is demonstrated. The resulting mixed crystals of various shapes and beautiful colors preserve the strong ... -
Colloidal optoelectronics of self-assembled quantum well superstructures
(Bilkent University, 2020-06)Advances in the colloidal nanocrystal synthesis enabled creation of quasi twodimensional colloidal quantum wells (CQWs) in the last decade. These CQWs possess similar properties to those of epitaxially grown quantum wells ... -
Comparison of electron and hole charge-discharge dynamics in germanium nanocrystal flash memories
(AIP Publishing, 2008-02)Electron and hole charge and discharge dynamics are studied on plasma enhanced chemical vapor deposition grown metal-oxide-silicon germanium nanocrystal flash memory devices. Electron and hole charge and discharge currents ... -
Computational modeling of quantum-confined impact ionization in Si nanocrystals embedded in SiO2
(2007)Injected carriers from the contacts to delocalized bulk states of the oxide matrix via Fowler-Nordheim tunneling can give rise to quantum-confined impact ionization (QCII) of the nanocrystal (NC) valence electrons. This ... -
Computational study of excitons and biexcitons in semiconductor core/shell nanocrystals of type I and type II
(Bilkent University, 2013)In this thesis, we studied electronic structure and optical properties of Type-I, Type-II, and quasi Type-II semiconductor nanocrystals (also known as colloidal quantum dots). For a parametric study, we developed quantum ... -
Computational study of power conversion and luminous efficiency performance for semiconductor quantum dot nanophosphors on light-emitting diodes
(Optical Society of America, 2012-01-30)We present power conversion efficiency (PCE) and luminous efficiency (LE) performance levels of high photometric quality white LEDs integrated with quantum dots (QDs) achieving an averaged color rendering index of >= 90 ... -
Critical role of CdSe nanoplatelets in color-converting CdSe/ZnS nanocrystals for InGaN/GaN light-emitting diodes
(OSA - The Optical Society, 2016)Here we report CdSe nanoplatelets that are incorporated into color-converting CdSe/ZnS nanocrystals for InGaN/GaN light-emitting diodes. The critical role of CdSe nanoplatelets as an exciton donor for the color conversion ... -
Dc-switchable and single-nanocrystal-addressable coherent population transfer
(2010)Achieving coherent population transfer in the solid-state is challenging compared to atomic systems due to closely spaced electronic states and fast decoherence. Here, within an atomistic pseudopotential theory, we offer ... -
Effects of rapid thermal annealing on the structural and local atomic properties of ZnO: Ge nanocomposite thin films
(A I P Publishing LLC, 2015)We have investigated the structural and local atomic properties of Ge nanocrystals (Ge-ncs) embedded ZnO (ZnO: Ge) thin films. The films were deposited by sequential sputtering of ZnO and Ge thin film layers on z-cut quartz ... -
Electroluminescence efficiency enhancement in quantum dot light-emitting diodes by embedding a silver nanoisland layer
(Wiley-VCH Verlag, 2015)A colloidal quantum dot light-emitting diode (QLED) is reported with substantially enhanced electroluminescence by embedding a thin layer of Ag nanoislands into hole transport layer. The maximum external quantum efficiency ... -
Electronic structure and optical properties of silicon nanocrystals along their aggregation stages
(Elsevier B.V., 2007)The structural control of silicon nanocrystals is an important technological problem. Typically, a distribution of nanocrystal sizes and shapes emerges under the uncontrolled aggregation of smaller clusters. The aim of ... -
Elements of nanocrystal high-field carrier transport modeling
(Wiley, 2007)Embedded semiconductor nanocrystals (NCs) within wide bandgap oxide materials are being considered for light emission and solar cell applications. One of the fundamental issues is the high-field transport in NCs. This ... -
Enhanced memory effect via quantum confinement in 16 nm InN nanoparticles embedded in ZnO charge trapping layer
(AIP Publishing, 2014)In this work, the fabrication of charge trapping memory cells with laser-synthesized indium-nitride nanoparticles (InN-NPs) embedded in ZnO charge trapping layer is demonstrated. Atomic layer deposited Al2O3 layers are ... -
Enhanced spontaneous emission in semiconductor nanocrystal solids using resonant energy transfer for integrated devices
(IEEE, 2008-11)Size-tuneable optical properties of semiconductor nanocrystal (NC) quantum dots make them attractive for a wide range of device applications. However, in these device applications, nanocrystals typically suffer from ... -
Enhancement of optical switching parameter and third-order optical nonlinearities in embedded Si nanocrystals: A theoretical assessment
(Elsevier, 2008)Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide band-gap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive ...
