Prospective study of copper sulfide nanofilms

This keynote talk will be devoted to describe hexagonal Cu₂S p-type semiconductor thin film fabrication using DC magnetron sputtering. Nanofilms with thickness gradient were successfully deposited by taking advantage of the deposition geometry and target dimensions. X-ray diffraction (XRD) analysis confirmed the exclusive formation of the hexagonal Cu₂S phase. Elemental composition and thickness dependence with sample position were determined using energy-dispersive x-ray spectroscopy (EDS). Optical properties, including the optical bandgap and refractive index were assessed by modeling transmittance spectra. XRD data analysis successfully determined the film thickness as a function of sample position, aligning well with thickness values derived from transmittance spectra analyses. These results were further supported by film thickness values obtained from cross-sectional scanning electron microscopy (SEM) images. Charge carrier density and mobility, extracted from the optical models, were found to be consistent with DC electrical measurements.

Professor De Morais (H62), PhD, full Professor of Physics at the University of Brasilia (UnB) – Brazil up to 2013. Appointed as UnB’s (Brazil) Emeritus Professor (2014); Visiting Professor at the Huazhong University of Science and Technology (HUST) – China (2012-2015); Distinguished Professor at the Anhui University (AHU) – China (2016-2019); Full Professor at the Catholic University of Brasília – Brazil since 2018; 2007 Master Research Prize from UnB. He held two-years (1987-1988) position with Bell Communications Research, New Jersey – USA. Doctoral degree in Solid State Physics (1986) from the Federal University of Minas Gerais – Brazil. With more than 14,500 citations, He has published more than 500 papers (Web of Science), delivered about 300 international invited talks (35 countries), and filed 16 patents.