Date of Award

Fall 2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Electrical and Computer Engineering

First Advisor

Lee, Chung Hoon

Second Advisor

Josse, Fabien J.

Third Advisor

Schneider, Susan C.

Abstract

This thesis presents the investigation of a nanoscale light-emitting diode (LED) device. The nanoscale LED has a great potential to be used as a light source for biomedical screening and fluorescence lifetime spectroscopy. It can also be developed to a single photon emitter for the application of quantum computing. The nano-LED has the electrical structure of a metal-semiconductor-metal (MSM) junction. The MSM junction has been formed on the nanogap device that is fabricated on a SOI wafer by optical lithography and KOH solution silicon etching. The Ni evaporated on the surface of the nanogap device performs the metal contact for the junction. The ZnO made by evaporation and thermal oxidation of Zn serves as the semiconductor part to realize efficient excitonic emission. Photon emission phenomenon has been observed when bias is applied to the nano-LED device. The measured IV curve has confirmed the junction structure. The electroluminescence spectrum of the light has been obtained by using monochromator and CCD camera. The spectrum shows broad visual band wavelengths that are believed to result from some intrinsic defects of ZnO. The electroluminescence mechanisms are explained by the recombination of electrons and holes injected through thermionic emission, field emission, and thermionic-field emission.

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