Evaluation of Textured TCOs for a-Si:H/µc-Si:H Thin Film Solar Cells by Angular Resolved Light Scattering Measurements

Transparent conductive oxides (TCO) are often used as transparent front electrodes for thin film solar cells. Besides their conductivity and transparency in the absorption range of the solar cell also the light scattering ability is important for light management. The TCOs are textured, e.g. as grown LPCVD ZnO:B or texture-etched ZnO:Al, and depending on their morphology they are differently adequate for their application as front electrode in solar cells. An evaluation method based on angular resolved light scattering (ARS) is presented in this paper. Measurement results and evaluation of different types of textured doped TCOs like reactively MF sputtered ZnO:Al (Zn:Al target), RF sputtered ZnO:Al (ZnO:Al2O3 target) and LPCVD ZnO:B are shown. A correlation between ARS and short-circuit density of a-Si:H/μc-Si:H p-i-n solar cells was found for LPCVD ZnO:B and reactively or RF sputtered and etched ZnO:Al until a saturation current was reached.