Influence of the grid and cell design on the power output of thin film Cu(InGa)Se-2 cells

摘要

The effect of the front contact characteristics on the working of monolithically integrated thin film solar panels and effective ways of improving the front contact are discussed. Efficiencies were calculated for various cell lengths and scribing areas in between cells (interconnection dead zone widths). The application of a metallic grid was studied to enhance the front contact. Both the efficiency and the cell length can be increased considerably. The exact benefit depends on the cell configuration and dimensions. This work presents quantitative analysis of the effects of a wide array of variables, such as cell length, sheet resistance of the transparent conductive oxide, interconnect dead zone, grid finger height, grid finger width and grid finger spacing. In addition to the cell efficiency, the calculated JV-curves are also presented, which bring more detail for a correct interpretation of the trends observed. Furthermore, the efficiencies were calculated using a set of 'virtual' transparent conductors with a sheet resistance between 0.1 and 10 Omega/sq and a fixed transmittance of 89.8%. By comparing the efficiency of these transparent conductors with the results obtained when using the fingers, the finger height can be translated to a virtual sheet resistance. (C) 2015 Elsevier B.V. All rights reserved.