Thesis (M.S.)--University of Florida, 2005. / Title from title page of source document. Document formatted into pages; contains 139 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 79-82). Also available in electronic version.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S.)--Oregon Graduate Center, 1987.

Oxide semiconductors have been envisaged to find applications in ubiquitous flexible electronics in daily life such as wearable electronic gadgets to offer novel user experiences. However, one of the bottlenecks to realise these applications is a lack of oxide-semiconductor components capable of wireless communications. As Bluetooth and Wi-Fi are the two dominant communication interfaces, fast enough front-end rectifiers must be developed to operate at their gigahertz (GHz) transmission frequencies. Furthermore, despite of significant developments of n-type oxide semiconductors in the last decade, widespread flexible electronics also requires high-performance p-type oxide semiconductors for use in complementary logic circuits. The objectives of this dissertation are to develop high quality Schottky barriers, achieve GHz speed Schottky diodes on rigid and flexible substrates, evaluate the noise properties of the Schottky diodes, develop p-type oxide semiconductor using sputtering technology, elucidate the hole transport mechanism in p type transistors, and demonstrate their potential applications such as radio receivers, complementary inverters and ring oscillators. First, indium gallium zinc oxide (IGZO) Schottky diodes were fabricated by using radio frequency magnetron sputtering. The oxygen content at the metal-IGZO interface was found to have a profound effect on the electrical performance. By introducing 3% O2 during the deposition of Pt or IGZO, the diodes exhibited excellent electrical properties without requiring any annealing treatment, thus allowing for the realisation of flexible IGZO Schottky diodes. The high-frequency properties of Pt-IGZO Schottky diodes on glass substrates were optimised by testing a range of IGZO thicknesses and diode active areas. The achieved highest cut-off frequency was beyond 20 GHz, which is to the best of our knowledge the fastest oxide-semiconductor device to date. On flexible substrates, the diodes also showed cut-off frequencies up to 6.3 GHz, well beyond the critical benchmark speed of 2.45 GHz for typical wireless communications. In order to assess the feasibility of using IGZO Schottky diodes in practical applications, measurements were taken to discern their low-frequency noise properties. In the as-deposited diodes, logarithmic dependence of the noise spectral density on the applied bias was observed, revealing that the dominant noise was generated in the space-charge region at low biases and in the series-resistance region at high biases, respectively. After annealing the diodes, very different noise mechanism was observed and the interface-trap-induced noise dominated the noise spectra. As one of the most promising p-type oxide semiconductors, SnO was also studied at low temperatures in this thesis. The experiment revealed that hole-transport mechanism was governed by either band conduction or variable range hopping in different temperature ranges. Finally, the potential for fully oxide-based electronics was demonstrated by an amplitude-modulation radio receiver comprising of an IGZO Schottky diode as the demodulator and a complementary ring oscillator based on IGZO and SnO transistors. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of the University of Manchester's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.

Thesis (Masters Diploma (Electrical Engineering)--Cape Technikon, Cape Town,1991 / A detailed study into the development of a three phase motor drive, inverter and microprocessor controller using a scalar control method. No mathematical modelling of the system was done as the drive was built around available technology. The inverter circuit is of a Vo~tage source inverter configuration whicp uses MOSFETs switching at a base frequency of between 1.2 KHz and 2 KHz. Provision has been made for speed control and dynamic braking for special applications, since the drive is not going to be put into a specific application as yet, it was felt that only a basic control should be implemented and space should be left for special requests from prospective customers. The pulses for the inverter are generated from the HEF 4752 I.e. under the control of the micro processor thus giving the processor full control over the inverter and allowing it to change almost any parameter at any time. Although the report might seem to cover a lot of unimportant ground it is imperative that the reader is supplied with the back-ground information in order to understand where A.e. drives failed in the past and where A.e. drives are heading in the future. As well as where this drive seeks to use available technology to the best advantage.

M.Ing. (Electrical and Electronic Engineering) / This thesis covers the development of the Mosmatrix, a high speed, high power switch which is implemented with an array of mosfet switching elements. The switching performance of the Mosmatrix proves that is is possible to employ existing semiconductor technology to switch pulses of 1,5 Joule, several hundred Ampere at several kilovolt, in the microsecond and sub-microsecond regime. The switch has demonstrated rates of current rise in the order of lOkA per J.1s during tumon without the use of tum-on snubbers (magnetic assist) . The rate of current fall during tum-off has been of the same magnitude. No other switch has demonstrated this level of repetitive current interrupt ability. The work covers the properties, switching requirements anc' switching performance of mosfet switching elements as well as the development of an isolated drive circuit.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.