@article {nano12193268,
	title = {Copper-Arsenic-Sulfide Thin-Films from Local Raw Materials Deposited via RF Co-Sputtering for Photovoltaics},
	journal = {Nanomaterials},
	volume = {12},
	number = {19},
	year = {2022},
	note = {n/a},
	abstract = {<p>The inexorable increase of energy demand and the efficiency bottleneck of monocrystalline silicon solar cell technology is promoting the research and development of alternative photovoltaic materials. Copper-arsenic-sulfide (CAS) compounds are still rather unexplored in the literature, yet they have been regarded as promising candidates for use as p-type absorber in solar cells, owing to their broad raw material availability, suitable bandgap and high absorption coefficient. Here, a comprehensive study is presented on the structural and optoelectronic properties of CAS thin-films deposited via radio-frequency magnetron co-sputtering, using a commercial Cu target together with a Cu-As-S target with material obtained from local resources, specifically from mines in the Portuguese region of the Iberian Pyrite Belt. Raman and X-ray diffraction analysis confirm that the use of two targets results in films with pronounced stoichiometry gradients, suggesting a transition from amorphous CAS compounds to crystalline djurleite (Cu31S16), with the increasing proximity to the Cu target. Resistivity values from 4.7 m\&$\#$8486;\&middot;cm to 17.4 \&$\#$8486;\&middot;cm are obtained, being the lowest resistive films, those with pronounced sub-bandgap free-carrier absorption. The bandgap values range from 2.20 to 2.65 eV, indicating promising application as wide-bandgap semiconductors in third-generation (e.g., multi-junction) photovoltaic devices.</p>
},
	issn = {2079-4991},
	doi = {10.3390/nano12193268},
	url = {https://www.mdpi.com/2079-4991/12/19/3268},
	author = {Centeno, Pedro and Alexandre, Miguel and Neves, Filipe and Fortunato, Elvira and Martins, Rodrigo and {\'A}guas, Hugo and Mendes, Manuel J}
}
