Article ID Journal Published Year Pages File Type
1664118 Thin Solid Films 2016 9 Pages PDF
Abstract

•H2 doping improves optoelectronic properties of Al, F co-doped ZnO (AFZO) films.•Resistivity of AFZO films decreases to 4.4 × 10− 4 Ω-cm with the 3% H2/(Ar + H2) ratio.•AFZO films show high average visible transmittances of above 92%.•Efficiency of a-Si thin film solar cells is improved by AFZO:H as front electrode.

Aluminum and fluorine co-doped zinc oxide (AFZO) thin films were prepared in Ar + H2 atmospheres by rf magnetron sputtering at room temperature. The structural, electrical, and optical properties of the prepared films were investigated using X-ray diffraction, scanning electron microscopy, atomic force microscopy, Hall-effect measurement, X-ray photoelectron spectroscopy, and ultraviolet–visible spectrometry, and their dependence on deposition atmosphere (i.e. H2 / (H2 + Ar) ratio) was studied. The resulting films showed a (0 0 2) diffraction peak, indicating a typical wurtzite structure, and the optimal film crystallinity was obtained with the H2 / (H2 + Ar) ratio of 3%. The electrical resistivity of AFZO films decreased to 9.16 × 10− 4 Ω-cm, which was lower than ZnO:Al and ZnO:F films due to double doping effect of Al and F. The resistivity further decreased to below 5 × 10− 4 Ω-cm for the AFZO film with the H2 / (H2 + Ar) ratio of 3%–5%. All the films regardless of hydrogen content displayed high transmittances (> 92%) in the visible wavelength range. Applying the developed AFZO films as front transparent electrodes, amorphous Si thin film solar cells were fabricated and the open-circuit voltage, fill factor, and efficiency of the cell with the hydrogenated AFZO film were improved in contrast to those without the hydrogenated film.

Related Topics
Physical Sciences and Engineering Materials Science Nanotechnology
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