Analytical investigation of the effects of variable parameters on the efficiency of photovoltaic devices in electric power generation

Photovoltaic systems with low production budgets are systems that convert the light collected from the sun to direct-current, DC, without using any intermediate materials. Considering the cost and importance of obtaining energy, it is a useful method to get electricity from solar energy which is one of the renewable energy sources. The solar cell is a photovoltaic system. For the efficiency of photovoltaic systems, in general, it is necessary to work on the efficiency of the solar cell. In this study we work theoretically which is complementary to the experimental work and admits better intending in terms of time and cost. With the analytical equations obtained from the theoretical study, the expression based on the current and voltage produced by the light falling on the solar cell examined. In this work, generated mathematical expressions allow us to effort on the dependence of the current, of the voltage and of the power values that we will get from the solar cell on external variable parameters. The external variables are those that affect the efficiency of the solar cell. The current voltage and power voltage graphs of the solar cell are analyzed regard as the function of intensity of incident light, effect of temperature and doping-concentration values. In study, other than these parameters were kept in constant. Here, the analysis was made with Matlab and Mathematica like simulation program. Using these graphs, the occupancy factor and quantum efficiency values in a solar cell were calculated. So, it was observed that the magnitude of the short-circuit current and the open-gate voltage on the solar cell increased with increasing luminous flux. In this case, we have seen that the power value and efficiency obtained at the output of the solar cell increase. This showed us that photovoltaic systems will work more efficiently with the falling light and light-quality. The results were found good consistent with previous studies. The change in the temperature value which is an important parameter affecting the efficiency of the solar cells were investigated thru graphs of the current-voltage and power-voltage. As a result, there was a significant decrease in open-gate voltage compared to a small increase in short-circuit current when we only increased the temperature value while keeping other parameters constant affected efficiency. It can be said that the efficiency of photovoltaic systems decreases in regions where the temperature is high. This circumstance was found to be consistent with previous studies. We examined the graphs IV and PV generated with altering electron-hole concentration parameters. As a result of the circumstance, it was seen that the results obtained with doping, electron-hole concentration, correspond with the literature data.