iSES - Internet School Experimental System

Solar energy conversion

Assignment

1. Get acquainted with the experiment of a silicon photovoltaic cell.
2. Measure the volt-ampere characteristic of the cell in the dark, enter the data into the graph. In the forward direction, also construct a graph of the dependence of the logarithm of the current against the voltage and from the linear part of the graph determine the coefficient n at T = 300 K (based on equation 1).
3. Turn on the illumination of the cell and measure the volt-ampere characteristics for different values of light intensity and enter the data into a common graph.
4. Determine the filling factor FF according to equation 3 for individual illuminations.
5. Determine the efficiency of the cell from the following data: solar energy falling on 1 m² in 1 s is 750 joules, but the cell area is 1 cm². Determine the power from it as the product of J_m U_m for illumination of 40, 70 and 100 %. The lamp used does not have the same power as the Sun, so try also to calculate the efficiency of e.g. for energy of only 75 joules, if the illumination is 100 %.
6. Assume a large parallel resistance and try to calculate the size of the series resistance at 100 % illumination using the derivative dJ/dU at the point J = 0. Consider the light-generated current J_L as the short-circuit current, the current J₀ is obtained from the characteristic in the dark.

Note: it is advisable to process the results of tasks 4 and 5 in a table.