Influence of metal grid patterns on the performance of silicon solar cells at different illumination levels

In the present work we have investigated, both theoretically and experimentally, the effect of two different metal grid patterns, one with 2 busbars outside the active area (linear grid) and another one with a square busbar surrounding the active area (square grid) on the electrical performance of high efficiency c-Si solar cells under concentrated light (up to 200 suns). We calculated the power losses of both grid patterns at different illumination levels. We found that the power losses of the square grid are less sensitive to illumination levels compared to linear grid: this is true especially under medium and high concentration ratio. Moreover, the power losses of the square grid are also less influenced by metal grid resistivity. We fabricated and characterized also a large number of c-Si solar cells (more than 100 for each grid design) to prove the theoretical findings. (C) 2008 Elsevier B.V. All rights reserved.