Date of Award

Fall 2013

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics

First Advisor

David B. Janes

Committee Chair

David B. Janes

Committee Member 1

Yong P. Chen

Committee Member 2

Andrew S. Hirsch

Committee Member 3

Erica Carlson

Committee Member 4

Timothy D. Sands

Abstract

Das, Suprem R. Ph.D., Purdue University, December 2013. Nanoscale Semiconductor Materials and Devices employing Hybrid 1D and 2D structures for Tunable Electronic and Photonic Applications. Major Professor: Dr. David B. Janes.

Continued miniaturization of microelectronic devices over past decades has brought the device feature size towards the physical limit. Likewise, enormous `waste energy' in the form of self-heating in almost all of the electronic and optoelectronic devices needs an `energy-efficient low power' and `high performance' material as well as device with alternate geometry. III-V semiconductors are proven to be one of the alternate systems of materials for various applications including CMOS devices, low power and high performance transistor devices, power transistors, as well as thermoelectric applications. InSb, being the bulk semiconductor with lowest bandgap, highest mobility, low effective mass, and highest spin–orbit coupling has potential of providing numerous novel applications. Also, InSb in nanowire form has not been explored in many aspects. First part of this thesis explores the possibility of growing InSb nanowires using solution based electrodeposition technique followed by field effect transistor studies. InSb nanowires have recently shown very promising magneto-transport properties at low temperatures and with magnetic field due to its high spin orbit coupling. This thesis demonstrates initial low temperature device studies on hybrid devices with InSb channel and superconducting electrodes (aluminum). In the last section of InSb nanowire studies, the thesis explores hierarchial branched nanowires with different diameters that demonstrate near unity optical absorption in UV–VIS regime and wavelength dependent absorption in near infrared (NIR) regime. A photonic coupling model was developed to explain the phenomena. The unique photonic properties of the structurally tailored branched nanowire arrays could be used to devise new types of photonic, optoelectronics and/or photovoltaic devices.

The second half of the thesis explores another class of hybrid material structure involving 2D semiconductor/semimetal ‘Graphene’ and 1D silver nanowires. While the ultimate goal was to push the limit of ‘transparent and flexible technology’ the thesis, also critically explores the physics of percolation doping to beat the conduction–transparency bottleneck. The thesis demonstrates theory of ‘co-percolation’ involving two individual networks in which the invidual's weakness is circumvented by the other. This study not only applies to the particular system chosen but also could be readily applied to any large scale 2D–1D nanoscale systems such as layered semiconductors, topological insulators and nanowires.

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