الفهرس 
CHAPTER 1 IntroductionOnly 14 pages are availabe for public view
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Abstract
Ambient energy harvesting is the process where energy is obtained
from the environment. A variety of techniques are available for energy
scavenging, including solar and wind powers, ocean waves,
piezoelectricity, thermoelectricity, and physical motions. Some systems
convert random motions, including ocean waves, into useful electrical
energy that can be used by oceanographic monitoring wireless sensor nodes
for autonomous surveillance. Ambient energy sources are classified as
energy reservoirs, power distribution methods, or power-scavenging
methods, which may enable portable or wireless systems to be completely
battery independent and self-sustaining.
This thesis addresses different methods of parameters optimization
of the selected micro energy harvesting source thin-film solar cells. To
integrate the different energy harvesting techniques into one overall
system, taking advantage of the individual strengths of each technique.
The work in this thesis can be divided into three main parts. The
first part presents the grating shape, their dimension effects and the effect
of temperature variance on the optical, the electrical properties, and
therefore on the efficiency of the thin-film solar cells. The photovoltaic
(PV) efficiency was improved by 1.73 % in the case of using half circle
grating compared to the model without grating. The observation about the
temperature effect that the efficiency is increased for PV of surface grating
by about 4.87% compared to the free grating surface’s PV. The efficiency
of the PV efficiency is degraded when the temperature is increased above
300 K. After studying the effect of different types, we extract the equivalent
circuit of each thin-film solar with one type of presented grating type. The second part presents surface plasmon polaritons (SPPs) effects
on solar cell efficiency, series resistance, and shunt resistance were studied
and analyzed in this work. The different surface plasmon polaritons (SPPs)
shapes and their effects on the optical, electrical properties and therefore on
the efficiency of thin-film solar cells were also studied. The semiconductor
and electromagnetic models were incorporated for studying the electrical
and optical behaviors of the thin film solar cells, respectively. This study
was introduced by using the 3D numerical simulator, Multiphysics. A
14.76% efficiency was achieved for triangle’ SPPs of 1.07% improvement
compared to solar cell with SPPs free. Also the solar cell electrical
parameters were extracted in this work based on a single diode equivalent
model. The series resistance was decreased for solar cells of equilateral
triangle SPPs by 3% compared to the solar cell with free SPPs.
The third part presents the impact of surface plasmon polariton and
the temperature variance effect on the entire array of silicon thin-film solar
cells. The electromagnetic and semiconductor models were used to
investigate the optical and electrical properties of thin-film solar cells,
respectively. This study was introduced by using the 3D Multiphysics
COMSOL simulator. A 14.76% efficiency is achieved for triangle’ SPPs
of 1.07% improvement compared with a solar cell with SPPs free. Finally,
MATLAB/SIMULINK model based on mathematical equations was
introduced for thin-film solar cells to study the complete array. This method
is suggested to simulate the thin film array in a very short time.