Increased interest in the field of sensor technology stems from the availability of an inexpensive and robust sensor to detect and quantify the presence of a specific gas. Bulk p-CuO/n-ZnO heterocontact based gas sensors have been shown to exhibit the necessary sensitivity and selectivity characteristics, however, low interfacial CuO/ZnO contact...
The electrical properties of ion-implanted GaAs FET channels
are investigated by two methods. First, the channel current (I) as
a function of voltage (V) is examined at different temperatures and
using different voltage ramp rates. The standard FET I-V curve,
which can be observed on a commercial curve tracer, is...
The photoresponse behavior of semi-insulating GaAs is
investigated. The photocarrier lifetime is discussed and
the influence of surface and contact recombination is
taken into account. Photocurrent-voltage characteristics
have been measured and a mechanism for the gain in terms
of space charge amplification and avalanching is suggested.
The influence of deep...
The optical and electrical characteristics of semi-insulating GaAs photoconductive detectors made with ohmic and Schottky contacts are studied in this thesis. Current - voltage measurements are made both in the dark and under varying power levels of HeNe laser (6328 Å) illumination. DC photocurrent gain is then calculated as a...
High speed photodetectors are a necessary element in
broad band digital and analog optical communication systems.
In this thesis easily integrable planar high speed
photodetectors made on undoped semi-insulating (SI) GaAs
substrates are modeled and tested. The fabrication process
of the detectors is fully compatible with GaAs
metal-semiconductor field effect...
Mercury cadmium telluride is important in the detection
of electromagnetic radiation in the eight to twelve micron
atmospheric window for infrared imaging systems. High
resolution infrared imaging systems use either large (256x256
element to 1024x1024 element) staring arrays or much smaller
(1-6 element) scanned arrays in which the image is...
Typical power outputs of commercially available diode lasers are on the
order of 5 milliwatts. This thesis discusses the growth, processing and
fabrication of high power (lOO's of milliwatts) diode lasers. Devices were
grown by Molecular Beam Epitaxy (MBE) and by Metal Organic Chemical
Vapor Deposition (MOCVD). The MOCVD diode...
Dielectric waveguides are becoming important for their numerous
applications in integrated optics. The study of dielectric waveguides by analytical
techniques is not sufficient for many variations in waveguide shape, anisotropy,
and inhomogeneity commonly encountered in waveguide materials. This work
studies the finite element method as an accurate tool for the...