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Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available online.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

In this thesis steady-state (i.e. steady-state with respect to the applied voltage waveform) transient current-transient voltage [i(t)-v(t)], transient brightness-transient current [b(t)-i(t)], transient brightness-transient voltage [b(t)-v(t)], transient current [i(t)], transient brightness [b(t)], and detrapped charge analysis are introduced as novel organic light emitting device (OLED) characterization methods. These analysis methods involve measurement of the instantaneous voltage [v(t)] across, the instantaneous current [i(t)] through, and the instantaneous brightness [b(t)] from an OLED when it is subjected to a bipolar, piecewise-linear applied voltage waveform. The utility of these characterization methods is demonstrated via comparison of different types of OLEDs and polymer light emitting devices (PLEDs) and from a preliminary study of OLED aging. Some of the device parameters obtained from these characterization methods include: OLED capacitance, accumulated charge, electron transport layer (ETL) thickness, hole transport layer (HTL) thickness, OLED thickness, parallel resistance, and series resistance. A current bump observed in i(t)-v(t) curves is attributed to the removal of accumulated hole charge from the ETL/HTL interface and is only observed in heterojunctions (i.e. OLEDs), not in single-layer devices (i.e. PLEDs). Using the characterization methods developed in this thesis, two important OLED device physics conclusions are obtained: (1) Hole accumulation at the ETL/HTL interface plays an important role in establishing balanced charge injection of electrons and holes into the OLED. (2) The ETL behaves as a leaky insulator while the HTL more efficiently conducts charge and acts as a voltage-dependent resistor. A preliminary investigation of the aging properties of OLEDs is presented as further evidence of the utility of the novel characterization methods developed in this thesis. In general, aging is characterized by a softer turn on of the forward bias portions of i(t)-v(t) and b(t)-v(t) curves. Also, some aging recovery is possible if the OLEDs are subjected to a zero or reverse bias. / Graduation date: 2000

The electronegativities of -SF���, -CF���SO���, and -SO���F have been measured with gas phase X-ray photoelectron spectroscopy. Of these three groups previously measured values were found only for -SF���. The electronegativities of -Cl, -Br, -CF���, and -CF���, were concurrently measured to determine how the findings of this research compare with other experimental values found in the literature. Our experimental electronegativities for -SF���, -CF���SO���, and -SO���F are 2.81 �� 0.12, 2.49 �� 0.09, and 2.92 �� 0.12 respectively. The electronegativity of -CF���, currently measured (2.78 �� 0.08) is significantly lower than other experimental values. The electronegativity of -SF��� is in agreement with other experimental values. The experimental electronegativities are compared with theoretical values calculated based on the assumption of Electronegativity Equalization and based on Mulliken's definition of electronegativity. It is found that the electronegativities calculated with Electronegativity Equalization are higher than the experimental values currently measured, and those calculated with Mulliken's definition are lower than the experimental values. / Graduation date: 1999

Graduation date: 1998

Thesis (M.Sc.)--York University, 2004. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 88-93). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: LINK NOT YET AVAILABLE.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Nov. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Chemistry, University of Alberta." Includes bibliographical references.