Electrical characterization of cadmium zinc telluride nanowires for use as a gamma radiation detector: Modeling and experimentation

Cadmium Zinc Telluride (CZT) is a universal single crystal room temperature ternary compound semiconductor used for radiation detection. These semiconductor detectors are limited to a size of 2mm wafers and the cost to create low defect density samples is very high.;The purpose of this thesis is to measure the electrical characteristics of CZT nanowires electrodeposited onto a titanium dioxide (TiO2) nanotubular template grown from titanium (Ti) substrate. Voltage-current (V-I) characteristics were measured to test the feasibility of using this material as a detector of gamma radiation. First the measurements were conducted on single CZT nanowire samples, and then on stacked arrays of multiple samples connected in series. The experiments used two low energy radiation sources, Americium-241, a source of 60keV, 4muCurie gamma radiation and Iodine-129 a source of 30keV, 0.1muCurie x ray radiation. These sources are calibration tools obtained from the National Institute of Standards and Technology (NIST). The experiments show that the stacked arrays of CZT nanowire samples are good candidates for detecting low energy gamma radiation at room temperature.;Unexplained oscillations in the V-I characteristics were thought to be related to defects in the material or due to possible penetration of the silver (Ag) epoxy that was used for making electrical contact with the gold (Au) sputtered electrodes. This possibility was numerically modeled by software Maxwell 3DRTM (Ansoft Co., Canonsburg, PA, version 11.1).;In addition to the V-I characteristic measurements, an attempt was made to incorporate the CZT nanowire array detector array into a spectrometer setup. Preliminary measurements did not show any response from the CZT nanowire array to gamma radiation. Suggestions are made in the thesis for improving the detector design that would potentially lead to a response to gamma radiation.