Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"n-type doping"”.
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N-type doping of organic thin films using a novel class of dopants
I present a new approach to stable n-type doping of organic matrices using organic dopants. In order to circumvent stability limitations of strong organic donors, I produce the donor from a stable precursor compound in situ. As an example, the cationic dye pyronin B chloride is studied as a dopant …
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Novel dopants for n-type doping of electron transport materials: cationic dyes and their bases
… of silicon technology showed that controlled doping was a key step for the realization of e®ective, stable and reproducible devices. When the conduction type was no longer determined by impurities but could be controlled by doping, the breakthrough of classical microelectronics became …
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THE ROLE OF NATIVE POINT DEFECTS AND SURFACE CHEMICAL REACTIONS IN THE FORMATION OF SCHOTTKY BARRIERS AND HIGH N-TYPE DOPING IN ZINC OXIDE
… contacts and high, yet controllable, n- and p-type doping. The scope of this work explores the electronic properties of ZnO surfaces and interfaces and the impact of native point defects on Schottky barrier formation and doping.</p><p>The results presented here use a complement of …
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Selective SiGe nanostructures
… morphology during growth, and the effects of n-type doping on selective growth. We have also fabricated extremely sharp p-n diode doping profiles. With the above accomplishments we have demonstrated the feasibility of vertical MOSFET fabrication through selective epitaxial growth. To realize the …
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Controlled growth and doping of core-shell GaAs-based nanowires
… effect of the Au seed nanoparticle during n-type doping was identified and n-type doping was achieved via the removal of the Au nanoparticle prior to doping. A combination of energy dispersive X-ray spectroscopy, current-voltage, capacitance-voltage, and Kelvin probe force microscopy …
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Materials science and design for germanium monolithic light source on silicon
… emitter for Si photonics. Tensile strain and n-type doping are two key properties in Ge to achieve optical gain. This thesis mainly focuses on: (1) physical understandings of the threshold behavior of Ge-on-Si bulk laser and the temperature dependent performance; (2) process developments to grow …
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Ge-on-Si light-emitting materials and devices for silicon photonics
… L valleys with extrinsic electrons from n-type dopants. Our theoretical calculation using a direct band-to-band transition model has shown great benefit of tensile strain and n-type doping on the direct gap optical gain characteristics. By considering free carrier absorption which dominates …
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An investigation into the use of group VI elements as dopants in III-V materials prepared by molecular beam epitaxy
… controllable source of S2 or Se2 molecules for n-type doping of GaAs and Ga1As grown by Molecular Beam Epitaxy (MBE). This source produces a pure oeam ot chalcogen dimers at low temperature (200-300°C) and is simply programmed by an applied emf. The response time of the cell is of the order of one …
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Ge-on-Si laser for silicon photonics
… Through the use of tensile strain and heavy doping, Ge exhibits properties thought exclusive of direct band gap materials. Dependence on temperature suggests strong interaction between indirect bands, [Delta] and L, and the direct band gap at [Gamma]. The behavior is justified through …
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Physical mechanism of a capacitance-based graphene humidity sensor
… on the surface of the substrate can induce n-type doing effect to graphene. Then the device is brought into dry air, where O 2 molecules will enter between graphene and the substrate and fill the vacancies, which eliminates the n-type doping effect. O 2 molecules also appear on the top of …
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Fabrication and Characterization of Aluminum Nano-Carbon Composites and Investigation of Their Electrical Conductivity
… through the lattice of the metal. Through n-type doping from the metal to the nano-structures the electron density at the interface of nano-crystalline graphite and the metal lattice increases thereby enhancing the bulk electrical conductivity. We identify the important fabrication parameters …
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Electronic devices based on 2D material: fabrication, characterization and analysis
… Black phosphorus capacitors with various types of gate dielectrics were fabricated and measured at varying temperatures. From the temperature dependence of the transition frequency, we determined the bandgap of the ~50 nm black phosphorus is 0.31 eV, while, from electrostatic models, our …
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OPTICAL CHARACTERIZATION OF WIDE ENERGY AGP GROUP III-NITRIDE SEMICONDUCTORS
… were measured for a series of undoped GaN and n-type GaN thin films as well as InGaN alloys of low indium compositions grown on (1000)-plane sapphire substrates. Free exciton transitions, bound exciton transitions and longitudinal optical (LO) phonon-assisted exciton transitions were observed in …
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Nanoscale electrical characterisation of nitride structures
… To achieve an insulating buffer layer, carbon doping is usually used to compensate the unintentional n-type doping of nitride materials. Here, I show that vertical leakage can originate from the formation of inverted hexagonal pyramidal defects during the low temperature growth of an AlGaN:C …
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Charge and Thermoelectric Transport in Metal Halide Perovskite Semiconductors
… FETs. Prolonged channel bias leads to enhanced n-type doping at the contact interface, resulting in increased device conductivity. This research also extended to investigating electroactive A-site molecules on charge transport in alkyl-diammonium 2D/3D perovskite FETs (Chapter 4.1), and pure *n*=1 …
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Wide band-gap nanowires for light emitting diodes
… properties and we observed both demonstrative ptype and n-type doping, dependent on processing conditions, using individual nanowire electrical characterization. Thus, by achieving ZnO nanowire arrays with controlled nanowire areal density, excellent length uniformity and vertical alignment …
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Quantum and atomistic simulation of mechanical and electronic properties of nano-materials
… band gap significantly. It also induces the n-type doping effect on MoS2. Defects on MoS2 (Mo and S) introduce the finite states in the middle of band gap. In addition, the application of an electric field significantly affects the band gap depending on the direction of the field.
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AB initio study and design of 2D materials/III-nitrides-based post-CMOS devices using first-principles multiphysics simulation framework
… the most promising element candidates for p-doping of MoS2. Specifically, we found VB group impurity elements, such as Ta, substituting Mo to achieve negative formation energy values with impurity states all sitting at less than 0.1 eV from the valence band maximum (VBM), making them the …