الفهرس 
EXPERIMENTAL TECHNIqUEOnly 14 pages are availabe for public view
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Abstract
The objective of the thesis is to analyse and design
photovoltaic solar cells which convert the solar radiation
into electricity. It is very important for developing coun-
tries such as Egypt to have low cost sources of energy, particularly
solar energy.
The various types of solar energy conversion to electri-
city; solar cell characteristics and previous work on Zinc
Telluride thin films are presented and explained here.
Zinc Telluride (Z T ) thin films in the thickness range
n e
from 525Ao to 4000Ao were prepared with deposition rate of
2Ao/sec by thermal evaporation technique under a vacuum of
10-5 Torr. X-ray investigations showed that the film of thickness
llOOAo has a cubic structure and the others havi1lgthickness ranging
from 22OOAo ”to 4000Ao, have hexagonal structures. The energy band
gap of ZnTe thin films deposited onto quartz substrates was
determined in the spectral range from 3000Ao to 8000Ao. It was
found that Z T material has an optical ’energy band gap of
n e
The electrical measurements of the films have
2.23eV.
shown that the film resistance always decreases with increasing
the sample temperature. The thermal activation energy of
the conduction electrons of the films was varied from 0.157eV.
to 1.034eV, with the variation of film thickness The measurements of the dark I-V characteristics of
ZnTe/Si heterojunctions showed that increasing temperature and
p-layer thickness, the slope of the I-V characteristics in the
forward direction decreased. Also both series resistance, shunt
resistance; and activation energy of conduction electrons
increased with increasing the p-Iayer thickness.
The measurements of the I-V characteristics of Z T IS.
n e 1
heterojunctions under normal illumination showed that with
increasing the p-Iayer thickness the open circuit voltage; the
maximum output voltage, the output power, and the fill factor
were increased. While, the short circuit current and the maximum
output current were decreased with increasing the p-layer
thickness.
The output power of Z T IS. heterojunction was measured
n e 1
and it was found in the order of micro watts which is considered
very small. The spectral response curves of Z T IS.
heterojunction showed that there are two peaks at the wavelenngthes
SSO and I07Snm, which belong to the materials used in
the heterojunction.