Organic field-effect transistors (OFETs) with region-regular poly(3-hexylthiophene) (rr-P3HT) as active semiconductor were fabricated and characterized. Various methods for improving device performance were investigated. These methods include: the use of dip coating technique (rather than spin coating), thermal annealing, polymer doping with iron chloride (FeCl 3), and stamping of "dry" poly(dimethylsiloxane) (PDMS) stamp before polymer deposition. / Through experimental results, it is clear that thermal annealing increases charge carrier mobility of P3HT OFETs. On average an increase of four times in charge mobility was observed after thermal annealing was performed. Dip coated samples also resulted in higher mobility values than spin coated samples. Highest charge mobility value achieved were was ∼0.02 cm2/Vs for dip coated samples, where as the highest value for spin coated devices was around 6e-3 cm2/Vs. / "Dry" stamping of a PDMS devices yielded devices with higher mobility values by around 100% compared to unstamped counterparts. These devices also exhibited lower parasitic leakage currents. / Devices doped with FeCl3 did not perform very well. It is suspected that it was increased so much that it became impossible to turn off the devices.

Thesis (M.S. in Electrical Engineering)--Washington State University. / Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 144-149).

No description available.

Thesis (M. Eng.)--Carleton University, 2002. / Includes bibliographical references (p. 76-81). Also available in electronic format on the Internet.

The conversion gain of GaAs MESFET mixers is known to be dependent on the impedances seen by the applied signals and the resulting mixing products at all ports of the device. For an accurate representation, all these loading conditions should be considered; however, the design of gate and drain networks then becomes rather difficult. As a result, no sufficiently accurate and yet usable design procedures exist for MESFET mixers; instead, a few simple rules involving short- and open-circuit terminations have been given by various authors. Unfortunately, these rules are often inappropriate, particularly in upconverter applications. In this thesis, the conversion efficiency dependence on the drain loading at the local oscillator frequency has been studied for a gate upconverter; the local oscillator signal is by far the most dominant in terms of its influence on mixer performance. It has been found that the conversion gain can significantly deteriorate for a narrow range of load values. In addition, the local oscillator drain termination resulting in highest gain has been found to be generally different from the short-circuit recommended in the literature. Based on these findings, a novel FET upconverter design procedure has been developed that incorporates the local oscillator loading phenomenon in the FET equivalent circuit by means of a load dependent mixing transconductance. It allows the optimization of the drain network for an acceptable match at the selected sideband and desired local oscillator rejection while avoiding impedance values in the local oscillator frequency range which would otherwise cause severe degradation in conversion gain. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

No description available.

As Si MOS approaches its maximum limits in speed and bandwidth, new devices are desired to meet the needs of high speed communications and signal processing. A device that exhibits superior performance to Si MOS, BJT, and GaAs technology is the HEMT (high electron mobility transistor). The HEMT offers superior transconductance, mobility, speed, and noise performance compared to Si MOS, BJT, and standard GaAs technology. The high performance is a result of improved channel mobility due to a heterojunction. At the heterointerface, the majority carriers are confined to a very thin sheet forming what has been termed a 2DEG (two dimensional electron gas). The purpose of this thesis is to demonstrate the suitability of Honeywell's delta-doped self-aligned complimentary HIGFET process for the realization of high speed analog circuits. An operational amplifier and switched-capacitor circuit are presented. The operational amplifier has been fabricated at Honeywell and preliminary tests have been performed on the op-amp which are also presented. / Graduation date: 1998

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

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references. Also available in electronic version.