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No description available.

Concentrator solar cells operate under the conditions of non-uniform illumination and varying spectral content of incident sunlight. To predict the performance of such cells, an analytical model must account for varying carrier photogeneration rates within the cell. Further, the back surface junction fabricated to reduce recombination at the back contact must be included in the analysis.Most models of n+-p-p+ cells assume uniform generation rates within individual layers. In this study, a one-dimensional n+-p-p+ concentrator solar cell is modeled for all levels of illumination of incident sunlight. The photocarrier generation rate is considered as non-uniform in each layer of the cell. An absorption model is incorporated to permit the application for various spectral mixes of incident sunlight. The model also includes the effects of finite surface recombination velocities at the surfaces. Carrier transport equations for the three layers of the cell are developed and solved for the excess carrier concentrations under the assumptions of the model. Junction current density-voltage relationships for the two junctions of the cell are derived. The use of the current density equations in the evaluation of cell performance is discussed. / Department of Physics and Astronomy

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 87-90). Also available via the Internet.

Thesis (M.E.E.)--University of Delaware, 2008. / Principal faculty advisor: Allen Barnett, Dept. of Electrical & Computer Engineering. Includes bibliographical references.

Thesis (M.S.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 69-70). Also available via Humboldt Digital Scholar.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Mary E. Galvin-Donoghue, Dept. of Materials Science & Engineering. Includes bibliographical references.

Prepared under contract no. EX-76-A-01-2295-037.

The purpose of this investigation is to compare high frequency to low frequency (50Hz) technologies. To accomplish this, two highly optimized candidate converters are built to champion each of the inverter classes. Both candidates are constrained to produce the same quasi-sinusoidal output waveforms in identical operating conditions. The low frequency inverter is designed with optimization of its output power quality and accurate loss characterization taken in mind. A new iron core design procedure is proposed that may predict core losses when using non-sinusoidal excitation. Experimental results indicate that it has a promising degree of accuracy. The high frequency candidate is designed using planar integration technology. A topology selection determines that a critical-conduction mode flyback is the most suitable option. Components are added the topology to allow resonant switching for reduced switching losses. Common-mode current arising from good capacitive coupling between windings in the planar coupled inductor is reduced using charge balancing technology. The novelty of the converter lies is in the fact that all passive components, barring the bulk of the input capacitance and the output capacitance, are incorporated into the single planar structure. Finally, a comparison of the inverters is made in the categories of power quality, regulation, efficiency, robustness and applicability to the application. The high frequency inverter is found to promise substantial advantages over the low frequency variety in most of these elements. / Dr. I.W. Hofsajer

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy