Minimization of the Series Resistance in Solar Cell Having a Circular Grid Design Under High Illumination
Ali Cheknane, B. Bentoucef, J-P Charles and R. Zerdoum
The aim of this work is to minimalize the series resistance of solar cell in order to increase the conversion efficiency of the solar cells under high concentration of solar radiation. A circular grid pattern is considered here and its dimensions are optimized to improve the conversion efficiency. The series resistance consists of several contributions: the lateral emitter, the contact resistance of metal/semiconductor, and the grid resistance. It is generally found that the series resistance of solar cells should be no more than a few tenths of ohms/cm2. The series resistance increases with light intensity and this is related to high generated photocurrent. As a consequence the loss by Joule effect becomes important. In fact, there is an antagonism between the shadowing effect and the series resistance effect. We try to find a compromise between these two effects to attain a maximum conversion efficiency. Our modelization results are 5.45% shadow loss fraction for the optimum radius and a square resistance equal to 50W/square and 7% for a square resistance equal to 100 W/square.