Self-textured Al-doped ZnO transparent conducting oxide for p-i-n a-Si:H thin film solar cell

Transparent conductive oxides (TCOs) play an important role in thin-film solar cells in terms of low cost and performance improvement. Al-doped ZnO (AZO) is a very promising material for thin-film solar cellfabrication because of the wide availability of its constituent raw materials and its low cost. In this study, AZO films were prepared by low pressurechemical vapor deposition (LPCVD) using trimethylaluminum (TMA), diethylzinc(DEZ), and water vapor. In order to improve the absorbance of light, atypical surface texturing method is wet etching of front electrode using chemical solution. Alternatively, LPCVD can create a rough surface during deposition. This "self-texturing" is a very useful technique, which can eliminate additional chemical texturing process. The introduction of a TMA doping source has a strong influence on resistivity and the diffusion of light in a wide wavelength range.The haze factor of AZO up to a value of 43 % at 600 nm was achieved without an additional surface texturing process by simple TMA doping. The use of AZO TCO resulted in energy conversion efficiencies of 7.7 % when it was applied to thep-i-n a-Si:H thin film solar cell, which was comparable to commercially available fluorine doped tin oxide ($SnO_2$:F).