CIGS cells with metallized front contact: Longer cells and higher efficiency

We have investigated the benefit of a patterned metallization on top of a transparent conductive oxide in CIGS thin-film solar panels. It was found that cells with a grid have a higher efficiency compared to cells with only a TCO. This was observed for all cell lengths used. Furthermore, metallic grids enable increase of the cell length up to 10 mm virtually without reduction in efficiency. This result was obtained with a metallic grid of 20 mu m wide and just 1.5 mu m high. In addition, the following parameters were varied: TCO sheet resistance, the grid finger width and the finger height for cell lengths up to 40 mm. For cell lengths of 30 mm and 40 mm, wider and higher fingers have improved efficiency compared to fingers of 20 mu m wide and 1.5 mu m high, which is related to a higher fill factor. (C) 2017 Elsevier Ltd. All rights reserved.