Fabrication Techniques for Unusual Electronic Systems: Silicon Microstructures for Photovoltaic Modules

171 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009.This thesis presents the fabrication of semiconductor wires, ribbons or bars by using special etching, top down approaches, and a printed assembly of optical and electronics systems by using elastomeric stamps. I describe three related topics of my dissertation research which involve forming structures and assembling them by structured or non-structured elastomers: (i) First, a new type, low-cost and versatile microstructured silicon form factor which is fabricated via top-down approaches. These form factors can be used as active films in high performance thin-film transistors and unconventional silicon photovoltaic modules. The first form factors reported are silicon nanoribbons with submicron spatial dimensions for macroelectronic circuits. Although devices built with these non-optimized nanoribbons show good electrical properties and performance, their intrinsic properties lead to unwanted defects which limit there application possibilities (ii) An optimized silicon form factor consisting of silicon microbars which can be used as active absorbers for the fabrication of micro photovoltaic devices is presented. The as-fabricated microstructured materials can be used to produce high performance and bendable silicon transistors and photovoltaic modules composed of silicon microcells with reduced purity requirements, high voltage outputs, and mechanically flexible designs. These specific applications are a result of their microscale design combined with the ability to manipulate the material, in a practical way, by using elastomeric stamps (PDMS). The slabs of PDMS that are used for printing and assembling these semiconductor materials can also be used for fabricating templates for sensor applications. (iii) We demonstrate the use of elastomeric stamps for the fabrication of nanostructured substrates for use in surface enhanced Raman scattering (SERS). Collectively, the results show that the use of PDMS stamps, inorganic materials, design layout and performance are suitable for developing unconventional high performance transistors, Si PV modules and sensors which cannot be achieved with conventional technologies.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD