We derive an analytical model for the depletion capacitance of silicon-on-insulator (SOI) optical modulation diodes. This model accurately describes the parasitic fringe capacitances due to a lateral pn junction and can be extended to other geometries, such as vertical and interleaved junctions. Analytical results show excellent agreement with numerical simulations. The model is used to identify the waveguide slab to rib height ratio as a key geometric scaling parameter for the modulation e ciency and bandwidth for lateral diodes. We characterise the fringe capacitance as a parasitic e ffect that leads to a decrease of about 20% in modulation bandwidth of typical SOI diodes without a corresponding increase in modulation effi ciency. From the scaling relations, the most e ffective way to increase the modulation bandwidth is to reduce the series resistance of the diode. In the light of our analysis, we propose high-speed and low power microdisk structures for future SOI modulators.

No description available.

No description available.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 110-118).

Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (p. 155-158). Also available via World Wide Web.

Thesis (Ph. D.)--Carleton University, 2002. / Includes bibliographical references (p. 185-200). Also available in electronic format on the Internet.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Ralph, Stephen; Committee Member: Citrin, David; Committee Member: Cressler, John; Committee Member: Denison, Douglas; Committee Member: Mukhopadhyay,Saibal. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph. D.)--School of Chemistry and Biochemistry, Georgia Institute of Technology, 2006. / Bredas, Jean-Luc, Committee Member ; Kippelen, Bernard, Committee Member ; Marder, Seth, Committee Chair ; Bunz, Uwe, Committee Member ; Perry, Joseph, Committee Member.

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2006. / Dr. C. P. Wong, Committee Member ; Dr. C. David Sherrill, Committee Member ; Dr. Thomas M. Orlando, Committee Member ; Dr. Mostafa A. El-Sayed, Committee Member ; Dr. Robert M. Dickson, Committee Chair.

Graphene and structurally similar 2-dimensional (2d) materials such as transition metal dichalcogenides (TMDs) and black phosphorus (BP) hold enormous potential for the next generation optoelectronics and photonics. Pairing 2d materials with printing is an emerging cost-effective large-scale device fabrication strategy. However, the current inks are far from ideal to support reproducible device fabrication. In addition, the instability of BP in ambient limits its applications. In this thesis, I present formulation of 2d material inks for inkjet printing for optoelectronic and photonic applications. To begin with, I produce mono- and few-layer 2d material flakes via ultrasonic assisted liquid phase exfoliation. This allows one-step formulation of a polymer stabilised graphene ink. For TMDs and BP, I design a binary solvent carrier for binder-free ink formulation. I show that these 2d material inks have optimal fluidic properties, drying dynamics and interaction with substrates for spatially uniform, highly controllable and print-to-print consistent large-scale printing on untreated substrates. In particular, the rapid ink drying at low temperatures leads to minimal oxidation of BP during ambient printing; the printed BP with passivation retains a stability over one month. On this basis, the printed graphene is employed as active sensing layer in CMOS integrated humidity sensors and as counter-electrodes in dye-sensitised solar cells, while the printed TMDs and BP are used to develop nonlinear photonic devices (i.e. saturable absorbers for femtosecond pulsed laser generation) and visible to near-infrared photodetectors (e.g. MoS$_2$ and BP/graphene/silicon hybrid photodetectors). Beyond inkjet printing, I present an ink formulation of commercial graphene nanoplatelets for roll-to-roll flexographic press ($\sim$100 m min$^{−1}$ printing speed). This allows hundreds of conductive electronic circuits to be printed in a minute for capacitive touchpads. Though I investigate only graphene, TMDs and BP, the ink formulation strategies can be effortlessly transferred to other 2d materials such as boron nitride, MXenes and mica. In addition to the demonstrated applications, printing of 2d materials can be potentially exploited to fabricate devices such as transistors, light emitters, energy storage conversion, and biosensors. This significantly expands the prospect of printable 2d material optoelectronics and photonics.