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Full-Text Articles in Physics
Conductivity Reversal In Silicon Doped With S And Zn, Abdulaziz Shavkatovich Mavlyanov, Nurullo Zikrillayev, Maruf Khaqqulov, Erkin Khaltursunov, Farhod Shakarov
Conductivity Reversal In Silicon Doped With S And Zn, Abdulaziz Shavkatovich Mavlyanov, Nurullo Zikrillayev, Maruf Khaqqulov, Erkin Khaltursunov, Farhod Shakarov
Acta of Turin Polytechnic University in Tashkent
Based on experimental results of investigation of type of conductivity of silicon samples doped with sulfur at Т=1250°С, and thereafter with zinc at T=1200°С, the authors put forward the hypothesis about self-assembly of “binary” elementary cells where atoms of elements of group II (Zn) and IV (S) allegedly form ZnS-type compounds in Si. The thermodynamic conditions required for buildup of such elementary cells and assembly of various associations in the basic lattice of silicon including self-assembly of ZnS clusters were theoretically determined and experimentally justified.
Investigation Of Optical Second Harmonic Generation From Si (100) With Process Tailored Surface & Embedded Ag Nanostructures For Advanced Si Nonlinear Nanophotonics, Gourav Bhowmik
Legacy Theses & Dissertations (2009 - 2024)
The challenge of current microelectronic architecture in transmission bandwidth and power consumption can be potentially solved by using silicon photonics technologies that are compatible with modern CMOS fabrication. One of the critical active photonic devices for Si photonics is a Si based optical modulator. Most of the reported silicon modulators rely on the free carrier plasma dispersion effect. In those cases, a weak change of the refractive index obtained by carrier accumulation, injection or depletion is utilized in a Mach-Zehnder interferometer or a microring resonator to achieve intensity modulation, rendering them difficult for chip-level implementation due to a large footprint …
Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small
Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small
Electronic Theses and Dissertations
The goal of this project is to design and develop a fabrication process for a silicon photovoltaic device which incorporates a nanohair textured p-n junction. The silicon nanowires are etched into a silicon wafer, comprising an epitaxial p-layer on n-substrate, via metal-assisted chemical etching (MACE). The resulting nanowires contain p-n junctions that lie along the length of the vertical nanowires. This construct has the potential to increase the optical bandwidth of a silicon photovoltaic device by allowing a greater amount of short wavelength light to reach the junction. In addition, the MACE method of nanofabrication has the potential for decreasing …
Photoluminescence From Gan Co-Doped With C And Si, Mykhailo Vorobiov
Photoluminescence From Gan Co-Doped With C And Si, Mykhailo Vorobiov
Theses and Dissertations
This thesis devoted to the experimental studies of yellow and blue luminescence (YL and BL relatively) bands in Gallium Nitride samples doped with C and Si. The band BLC was at first observed in the steady-state photoluminescence spectrum under high excitation intensities and discerned from BL1 and BL2 bands appearing in the same region of the spectrum. Using the time-resolved photoluminescence spectrum, we were able to determine the shape of the BLC and its position at 2.87 eV. Internal quantum efficiency of the YL band was estimated to be 90\%. The hole capture coefficient of the BLC …
Tailoring The Optical Properties Of Silicon With Ion Beam Created Nanostructures For Advanced Photonics Applications, Perveen Akhter
Tailoring The Optical Properties Of Silicon With Ion Beam Created Nanostructures For Advanced Photonics Applications, Perveen Akhter
Legacy Theses & Dissertations (2009 - 2024)
In today’s fast life, energy consumption has increased more than ever and with that the demand for a renewable and cleaner energy source as a substitute for the fossil fuels has also increased. Solar radiations are the ultimate source of energy but harvesting this energy in a cost effective way is a challenging task. Si is the dominating material for microelectronics and photovoltaics. But owing to its indirect band gap, Si is an inefficient light absorber, thus requiring a thickness of solar cells beyond tens of microns which increases the cost of solar energy. Therefore, techniques to increase light absorption …
Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton
Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton
Faculty Publications
Electron paramagnetic resonance (EPR) is used to identify a new and unique photoactive silicon-related point defect in single crystals of rutile TiO2. The importance of this defect lies in its assignment to interstitial silicon ions and the unexpected establishment of silicon impurities as a major hole trap in TiO2. Principal g values of this new S=1/2 center are 1.9159, 1.9377, and 1.9668 with principal axes along the [¯110],[001], and [110] directions, respectively. Hyperfine structure in the EPR spectrum shows the unpaired spin interacting equally with two Ti nuclei and unequally with two Si nuclei. These silicon …
Reflection High-Energy Electron Diffraction Studies Of Indium Phosphide (100) And Growth On Indium And Indium Nitride On Silicon (100), Mohamed Abd-Elsattar Hafez
Reflection High-Energy Electron Diffraction Studies Of Indium Phosphide (100) And Growth On Indium And Indium Nitride On Silicon (100), Mohamed Abd-Elsattar Hafez
Electrical & Computer Engineering Theses & Dissertations
Study of the effects of atomic hydrogen exposure on structure and morphology of semiconductor surfaces is important for fundamental properties and applications. In this dissertation, the electron yield of a hydrogen-cleaned indium phosphide (InP) surface was measured and correlated to the development of the surface morphology, which was monitored by in situ reflection high-energy electron diffraction (RHEED). Atomic hydrogen treatment produced a clean, well-ordered, and (2x4)-reconstructed InP(100) surface. The quantum efficiency, after activation to negative electron affinity, and the secondary electron emission were shown to increase with hydrogen cleaning time. RHEED patterns of low-index InP(100) surface were modified by the …
Compensation And Characterization Of Gallium Arsenide, Randy A. Roush
Compensation And Characterization Of Gallium Arsenide, Randy A. Roush
Electrical & Computer Engineering Theses & Dissertations
The properties of transition metals in gallium arsenide have been previously investigated extensively with respect to activation energies, but little effort has been made to correlate processing parameters with electronic characteristics. Diffusion of copper in gallium arsenide is of technological importance due to the development of GaAs:Cu bistable photoconductive devices. Several techniques are demonstrated in this work to develop and characterize compensated gallium arsenide wafers. The material is created by the thermal diffusion of copper into silicon-doped GaAs. Transition metals generally form deep and shallow acceptors in GaAs, and therefore compensation is possible by material processing such that the shallow …
Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola
Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola
Electrical & Computer Engineering Faculty Publications
The influence of the copper concentration in silicon-doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (NCu/NSi) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn-on and turn-off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.
Nanosecond Optical Quenching Of Photoconductivity In A Bulk Gaas Switch, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, S. T. Ko
Nanosecond Optical Quenching Of Photoconductivity In A Bulk Gaas Switch, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, S. T. Ko
Electrical & Computer Engineering Faculty Publications
Persistent photoconductivity in copper-compensated, silicon-doped semi-insulating gallium arsenide with a time constant as large as 30 µs has been excited by sub-band-gap laser radiation of photon energy greater than 1 eV. This photoconductivity has been quenched on a nanosecond time scale by laser radiation of photon energy less than 1 eV. The proven ability to turn the switch conductance on and off on command, and to scale the switch to high power could make this semiconductor material the basis of an optically controlled pulsed-power closing and opening switch.