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Showing 1 to 15 of 15 for “"Band offsets"”.
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The Effect of Growth Method on GaN Films and Their Interfaces with CdTe and CdS
… and MOCVD and CdTe and CdS to determine the band alignments, conduction and valence band offsets, and Fermi level positions. These interface studies will help determine basic properties to see if these GaN films can be incorporated in a CdTe solar cell to improve its efficiency. It was …
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Band Offset Measurements of ε-(InxGa1-x)2O3/AlN using X-ray Photoelectron Spectroscopy
… hold significant promise due to their ultra-wide band gap, tunable polarization properties, and optimized spectral response. In this regard, the ε-(In0.15Ga0.85)2O3 /AlN heterojunction has significant potential for high-performance optoelectronic devices, particularly in extreme environments, due …
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Electronic band structure of III-V quantum dots using tight-binding and the k.p approximation
… moments based tight-binding model for electronic band structure calculations are implemented for several cases relating to quantum dot nanostructures where various mechanical models are investigated. First, a comparison is made between the two for an equivalent sized ellipsoidal InAs/GaAs quantum …
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Electronic, Optical, and Thermal Properties of Reduced-Dimensional Semiconductors
… <italic>e.g.</italic>, quasiparticle: QP) band gap and optical excitations, by the first-principles approach based on DFT. Therefore, during my PhD study, I employed first-principles calculations based on DFT and MBPT to systematically study fundamental properties of typical …
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First principles simulation of amorphous silicon bulk, interfaces, and nanowires for photovoltaics
… region. We calculated for the first time band offsets of a-Si:H/c-Si heterojunctions from first principles and examined the influence of different surface orientations and amorphous layer thickness on the offsets and implications for device performance. The band offsets depend on the …
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Epitaxial growth and characterization of hexagonal boron nitride for deep UV applications
… the deep UV community of late. Due to its wide bandgap (~ 6 eV), hBN has a significant potential for deep ultraviolet (DUV) photonic device applications. Additionally, the high neutron capture cross-section of the isotope boron-10 makes hBN a unique material for neutron detector applications. …
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Defect energies, band alignments, and charge carrier recombination in polycrystalline Cu(In,Ga)(Se,S)2 alloys
This work investigates the defect energies, band alignments, and charge carrier recombination in polycrystalline Cu(In1-xGax)(Se1-ySy)2 chalcopyrite thin films and the interrelationship with the alloy composition. Photoluminescence spectroscopy of investigated Cu-poor Cu(In,Ga)(Se,S)2 layers …
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Incorporating double-heterojunction in anisotropic semiconductor nanocrystals for novel optoelectronic applications
… benefits of directionality and accessibility in band structure engineering and assembly. Here, we develop double heterojunction nanorods where two distinct semiconductor materials with type II staggered band offset are both in contact with one smaller band gap quantum dot. The double …
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Underlying Mechanisms of Halide Perovskites Properties and Metal Insulator Transitions in Vanadium Dioxide
… bonds leads to broad valence and conduction bands, along with the small band gap, resulting in small effective masses for both carriers. Another challenge is the long-term instability of perovskite solar cells due to the unstable cubic phase of halide perovskites and poor interfacial quality …
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Self-assembled strained nanostructures for light emission grown using molecular beam epitaxy
… controlled through size, composition, strain and band-offsets during epitaxial growth and can be tailored precisely to emit light with photon energies suited to the application, spanning 0.2-2.0 eV. This thesis explores two novel QD based light emitters in the visible and near-infrared wavelength …
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A study on the material and device characteristics of hafnium oxynitride MOSFETs with TaN gate electrodes
… a dielectric constant of 22 – 25, a large band gap of 5.6 eV with sufficient band offsets of larger than 1.5 eV, and is thermally stable in contact with silicon and metal gates. However, HfO2 is vulnerable to the diffusion of oxygen that causes formation of a low-k interfacial (silicon …
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Impact of Chemical States on the Effective Work Function of Metal Gate and High-kappa Dielectric Materials on Novel Heterostructures
… level shifts are only representative of the GaN band bending at the interface. If it is assumed that the core level shifts are only due to the oxidation of GaN, then the exhibited dipole at the GaN/GaON interface is -1.8 eV +/- 0.2 eV. Results indicate that the observed dipole is primarily caused …
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Study of silicon-on-insulator multiple-gate MOS structures including band-gap engineering and self heating effects
… for the source/drain regions materials with band–gap different from that of the channel material. This solution allows to increase the injection velocity of the particles travelling from the source into the channel, and therefore increase the performance of the transistor in terms of provided …
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Predictive simulation and design of III-V heterostructures for light emission and detection
… wave expansion method in conjunction with an 8-band k·p Hamiltonian to compute SL electronic structure, paying careful attention to the identification and mitigation of spurious solutions. The calculated SL eigenstates are then used directly to compute optical emission and absorption spectra, …