Efforts have been made to develop Al-doped ZnO films on glass as a transparent & conductive front electrode for amorphous or amorphous/ microcyrstalline thin film silicon solar cells. Compared to the well known Sn02:F films deposited by CVD, ZnO:Al technology allows for better performance at low cost because ZnO:Al can be textured in order to enhance light scattering into the cell. As a milestone towards industrial production, an optimised process for the reactive sputtering of ZnO:Al was developed. The process allows for initial cell efficiencies of more than 9% for single junction amorphous siliconsolar cells on commercial soda-lime float glass substrates. The crucial point for achieving high efficiencies is to optimise surface morphology after the wet etching roughening step due to the control of deposition parameters such as oxygen partial pressure.
