Description
This work investigates Zn(1−x)MgxO (ZMO) as a non-toxic, wide band gap buffer layer for CIGS and emerging Sb2S3 solar cells. The effect of Mg concentration on the chemical and electronic structure of ZMO films was investigated. The n-type layers were deposited via magnetron sputtering using targets with Mg concentrations varied, i.e., 5, 10, 15, and 20%, on molybdenum and double-polished sapphire substrates. The as-deposited films were characterized using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), reflection electron energy loss spectroscopy (REELS), and optical transmittance (UV-Vis). The films were grown at room temperature without substrate rotation, and the spatial variations in energy bandgap (Eg) and valence band maximum (VBM) values of ZMO were mapped over a distance of 10 cm. Our data indicate that the Eg of ZMO increases from 3.3 to 3.7 eV with increasing Mg content from 5 % to 20%. Moreover, for a given Mg content, ZMO films show a lower Eg value in the center of deposition compared to the edges. This trend was observed for band gap estimated from REELS (surface sensitive) and supported by UV-Vis (bulk sensitive). Moreover, the spatial fluctuations in ZMO band gap across the deposition area were found to be more pronounced for a higher Mg content. At the same time, the films grown using Mg 5%-ZnO target have negligible band gap fluctuations. On the other hand, VBM values do not show a clear trend as a function of Mg content in the target. Finally, the new outcomes will be presented on fabricating CIGS and Sb2S3 solar cells with ZMO as a n-type buffer layer.| Period | 27 May 2024 → 31 May 2024 |
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| Held at | European Materials Research Society, France |
| Degree of Recognition | International |