INVESTIGATION OF ELECTRONIC AND OPTICAL PROPERTIES DUE TO THE PRESENCE OF IRON (FE) ATOMS IN HEXAGONALIRON SULFIDE (H-FES) STRUCTURE

• Main Author: Sulistyowati, Ari
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81424
• Institution: Institut Teknologi Bandung

hexagonal-Iron sulfide (h-FeS) has significant potential for applications in various fields due to its unique property of transitioning from a semiconductor to a metal. However, the stoichiometry of h-FeS is challenging to achieve naturally due to iron (Fe) vacancies. The impact of Fe vacancies on its electronic and optical properties is not well understood. This study calculates the effects of Fe vacancies on the electronic and optical properties using density functional theory (DFT). An Fe vacancy concentration of 2.08% retains its semiconductor nature with a bandgap of 0.42 eV. However, increasing the Fe vacancy concentration to 4.16% and 8.33% changes its electronic structure to half-metallic. From its electronic properties, h-FeS with Fe vacancies can induce a metal-insulator transition (MIT). Its optical properties indicate that with or without Fe vacancies, the maximum absorption peak is at 932 nm in the infrared region. The structure with a 2.08% Fe vacancy has the highest absorption capability. These findings are beneficial for the development of medical devices and spintronic applications. Therefore, h-FeS with Fe vacancies opens significant opportunities for innovation in technologies combining semiconductor and metallic properties in one material.