Process monitoring of texture-etched high-rate ZnO:Al front contacts for silicon thin-film solar cells

In this study angular resolved scattering measurements are used to monitor the surface texture properties of sputter-etched ZnO:Al and to identify the influences of process parameter changes on the surface texture. Variations in pressure and temperature are possible drifts in the industrial fabrication that can influence the ZnO:Al properties. Therefore – with respect to industrial relevance – this study focuses on the influence of these parameters. Deposition parameter dependent trends in the angular resolved scattering are studied. Correlations between changes in the results of the angular resolved scattering measurements and the performance of a-Si:H/μc-Si:H tandem solar cells are shown. Additionally, it is demonstrated that the measurements can be used to optimize the surface texture of ZnO:Al for single-junction μc-Si:H solar cells by adjusting the deposition conditions according to the previously identified trends.