Accurate IV-measurement for back contact solar cells

Placing the electrical contacts of both polarities on the back side of a solar cell reduces shading losses and is therefore beneficial for the solar cell efficiency. Few concepts are already on the market but it is expected that a large break through of back contact solar cells is coming in near future. To determine the solar cell performance it is essential that the current-voltage-curve under illumination can be measured accurately with a temporary electrical contacting. In this paper we discuss the requirements for a certified measurement of the solar cell performance with respect to back contact solar cells. In the experimental section we show how these requirements are fulfilled by a measurement chuck constructed at Fraunhofer ISE.