Short circuit current vs cell thickness in solar cells under rear illumination: a direct evaluation of the diffusion length

The dependence of the short circuit current of a solar cell with its thickn ess is analysed for rear illumination. Under certain conditions, a simple l inear regression in a semilogarithm scale is found. Using these results, an almost direct evaluation of the minority carrier diffusion length in the b ase region of crystalline silicon solar cells is achieved. On the other han d, from the experimental point of view, monochromatic light is not required and the equipment requirements are minimised. The model presented in this paper is theoretically evaluated using a 1-dimensional simulation code. Som e preliminary experimental results are also shown. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.