Large-area CdS/CdTe solar cell with highly transparent sintered CdS layer

For the improvement of the transparency of CdS window layers produced by the printing and sintering method, a new substrate structure is proposed and examined. It is found that insertion of a TiO₂ and SiO₂ mixed layer between the glass substrate and CdS window layer diminishes the pores in CdS window layer. This is due to the good wettability between the CdS layer and TiO₂ -SiO₂. A CdTe solar cell with this CdS layer (2.8×10 cm²) has a high J_sc of 21 mA/cm². Another trial to achieve high package factor (the ratio of active-area/total-area) and high area productivity have also been carried out. By developing a wide-width writing method laser scribed CdTe/C double layer, the package factor increases from 85% to 90% and an efficiency of 8.7% is obtained in a 30×40 cm² submodule