الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Since the solar irradiation and illumination intensity are changed daily, due to the rotation of the earth around its own axis, which cause the consequence variation of day and night, and seasonally due to the rotation of the earth around the sun in an elliptical orbit, which cause the consequence variation of seasons. So, it is important to understand the effect of the illumination intensity and temperature on output performance parameters of mono crystalline and poly-crystalline silicon solar cells. The results of the two cells indicated that illumination intensity has a dominant effect on current parameters. It is found that photocurrent; short circuit current and maximum current have been increased linearly with increasing illumination intensity. So, concentrating systems may be regarded as a key choice to enhance the maximum power output of solar systems. The maximum power density of the mono-crystalline and poly-crystalline silicon increased from 2.24 and 1.93 mW/cm2 to 11.68 and 10.1mW/cm2 for illumination 0.2 and 1 Sun respectively. On the other hand, it has been observed that cell temperature has a dramatic effect on voltage parameters. Open circuit voltage and maximum voltage are decrease with increasing cell temperature. So, the maximum power density of the mono-crystalline and poly-crystalline silicon decreased from 10.85 and 12.19mW/cm2 to 9.08 and 10.47mW/cm2 for temperature 10oC and 50oC respectively. Although Crystalline silicon solar cells are the dominant technology in the commercial production of solar cells, accounting for more than 90% of the solar cell market. However, Silicon is not a perfect material for PV application due to its indirect band gap and high cost of fabrication. So, should be search for new materials for PV. Cuprous oxide (Cu2O) is a very promising material for the fabrication of solar cells due to the theoretical efficiency is approximately 20%, the direct band gap semiconductor (1.9?2.2eV), abundant, non-toxic, prepared with simple methods at very low cost and relatively high absorption coefficient over the wavelength range of the solar spectrum. Thin films of p- Cu2O and n- Cu2O were controllably prepared using electrochemical deposition method by using optimum condition for each type. Photocurrent experiments show that the Cu2O thin films synthesized in acid and alkaline media present n- Cu2O and p- Cu2O semiconductor character, respectively. The morphology and orientation were changed where p-Cu2O show pyramid shape with orientation (111) and n-Cu2O show dendritic shape with orientation (111) and (200).Optical characteristics of p-Cu2O and n-Cu2O were slightly affected. Homojunction Cu2O solar cells were electrochemically fabricated by consecutively depositing an n-Cu2O layer on a p-Cu2O layer. Then, evaporate gold on n- Cu2O. The best performance of the cell fabricated in this study was short-circuit current density 12.7mA/cm2, open-circuit voltage 31.5mV, fill factor 35%, and conversion efficiency 0.14% under STC. High short-circuit current density due to the pyramid-like surface structure of p- Cu2O caused the increase of the light path in the cell that could facilitate the photons to be absorbed more effectively. Low open-circuit voltage was due to energy band bending influence by interface states. The main limiting factor for the cell efficiency was the high resistivity of both p- Cu2O and n- Cu2O. Doping studies will be necessary to improve the performance of the homojunction Cu2O solar cells further.