UVM Theses and Dissertations
Format:
Print
Author:
Asante, Kofi
Dept./Program:
Electrical Engineering
Year:
2012
Degree:
Ph. D.
Abstract:
(Si-or SiGe)-insulator-Si substrates represents a key technology for the future development of high performance solid state devices that should operate at higher speeds, and lower powers. Existing SOI technologies are concerned with the fabrication of high performance information processing device. The research presented in this dissertation involves the processing required to produce a light trapping PV cell, fabricated on a novel CVD SOI substrate. The first part research focused on adapting a PECVD process to grow crystalline Si and SiGe film on a previously deposited yttria stabilized zirconia (YSZ) insulator layer at low temperature of 450°C.
Epitaxial thin-film solar cells are a viable solution to the goal of fabricating economical photovoltaic (PV) cells. A functional, light trapping, thin film PV is fabricated with a heteroepitaxial (YSZ) reflecting layer which also serves as a complaint layer for the growth of crystalline Si or SiGe active layers. X-ray analysis confirms that the deposited semiconductor layers were crystalline. It was observed that the YSZ reflecting layer produced an increase as hlgh as 35% in the photogenerated short circuit current, compared to the cells fabricated without the reflector layer.
The final component of this research focused on the development of microelectomechanical system (MEMS) based propulsion system for miniaturized satellites ("nanosats"). An essential feature of the micropropulsion system is the catalytic reactor responsible for the chemical decomposition of the monopropellant. This research designed and fabricated a micro-scale catalytic chamber on a Si substrate utilizing a self-assembled catalytic ruthenium dioxide nanostructures to chemically decompose a hydrogen peroxide (H₂O₂) monopropellant. The experimental results proved that the nanorods are capable of acting as a catalyst for decomposition of H₂O₂
Epitaxial thin-film solar cells are a viable solution to the goal of fabricating economical photovoltaic (PV) cells. A functional, light trapping, thin film PV is fabricated with a heteroepitaxial (YSZ) reflecting layer which also serves as a complaint layer for the growth of crystalline Si or SiGe active layers. X-ray analysis confirms that the deposited semiconductor layers were crystalline. It was observed that the YSZ reflecting layer produced an increase as hlgh as 35% in the photogenerated short circuit current, compared to the cells fabricated without the reflector layer.
The final component of this research focused on the development of microelectomechanical system (MEMS) based propulsion system for miniaturized satellites ("nanosats"). An essential feature of the micropropulsion system is the catalytic reactor responsible for the chemical decomposition of the monopropellant. This research designed and fabricated a micro-scale catalytic chamber on a Si substrate utilizing a self-assembled catalytic ruthenium dioxide nanostructures to chemically decompose a hydrogen peroxide (H₂O₂) monopropellant. The experimental results proved that the nanorods are capable of acting as a catalyst for decomposition of H₂O₂