Projection of solar cell back side contact to the LBIC image

摘要

This work presents a detailed analysis of the LBIC images with visible back side contact. The LBIC measurement for a solar cell local characterization has been developed and tested on mono-crystalline silicon solar cells. The solar cells were locally illuminated by a focused light source of different wavelengths. The response (current or potential) of the solar cell was measured at stationary conditions during the scanning process. A large number of independent data with high spatial resolution were obtained. Applying an advanced fitting procedure on these data yields a set of local parameters for each point on the solar cell, giving information on the distribution of the photo current, series, shunt resistance and lateral diffusion of minority carriers. The theoretical approach to this technique will be discussed and the applicability of this characterization tool will be demonstrated and compared. We have studied a group of silicon solar cells with good and wrong standard parameters. In this part we describe our study of the comparison between LBIC images with different wavelengths of the light source and explain the projection of back side contact of LBIC image by the theory of secondary emission of infrared light.