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...
This thesis investigates two methods of optical excitation of alternating-current thin-film electroluminescent (ACTFEL) devices. The two experimental methods investigated in this thesis are the photo-induced charge (PIQ) and luminescence (PIL), and the subthreshold-voltage induced transferred charge (VIQ) techniques. PIQ/PIL experiments utilize an above-bandgap laser pulse to investigate the transport properties...
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...
There is a new possibility of generating deep ultraviolet laser radiation from a solid-state source. With recent advances in material development, a new nonlinear optical crystal provides a greater damage threshold than current materials making higher conversion efficiencies possible.
This thesis examines the possibility of using this crystal to generate...
Polymer electrolyte membrane (PEM) fuel cells are being studied for use as high efficiency power plants in alternative fuel vehicles. To maintain high efficiency the operating temperatures of the membranes in these fuel cells must be closely monitored and controlled. However, the environment inside of the fuel cell is not...
In this report, the optical characteristics of ZnS:Tb AC driven thin-film
electroluminescent devices are evaluated. Luminescence at low and room temperature
under a constant phosphor field is recorded in order to probe the hot electron energy
distribution. Samples fabricated by atomic layer epitaxy and by sputter deposition are
investigated and...
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...