Sumbal Jamshaid

In this study, the effects of crucible-introduced elements (Al3+, Ti4+, Mg2+ and Y3+) on the structure, crystallization behavior, and electric properties of BaO-Bi2O3-TiO2-B2O3 glasses and glass-ceramics (GCs) were systematically investigated....

This work presents a combined theoretical and experimental investigation of optimized crystal structural and electronic properties of Ba-S compounds (BaS, BaS₂, BaS₃). Films were synthesized via e-beam evaporation followed by...

Chalcogenide perovskites are an emerging class of semiconductors particularly interesting for optoelectronic applications due to their high absorption coefficients and direct bandgaps of 1.7–1.9 eV. However, few processing routes have been developed for the synthesis of BaZrS₃ thin films. The advances in the fabrication of BaZrS₃ thin films using zirconium foil as precursor and substrate is a new strategy, which is compared with the results of BaZrS₃ thin films deposited on silicon carbide (SiC) substrate. In this study, a stacked layer methodology, inspired by the fabrication methods used for chalcopyrites and kesterites, is employed. The main objective is to facilitate the conversion of these layers into the desired perovskite structure through annealing. In methodology, we initiated the process by depositing elemental Zr by sputtering on SiC, followed by BaS on top of the Zr through electron beam evaporation and then sulphurized and annealed at high temperature (≈1000–1050 °C) to form BaZrS₃ in an inductively heated physical vapour transport setup in the presence of elemental sulphur. In the parallel approach the methodology remains same, with the sole deviation of zirconium foil, which act as both the substrate and the source. The successful synthesis of BaZrS₃ is confirmed by X‐Ray diffraction (XRD), scanning electron microscopy (SEM), and energy‐dispersive X‐Ray spectroscopy (EDS), while the optical band gap is analyzed by UV‐Vis. The microstructure of the BaZrS₃ films shows the polycrystalline structure and surface roughness.

Current research efforts in the field of the semiconducting chalcogenide perovskites are directed towards the fabrication of thin films and subsequently determine their performance in the photovoltaic application. These efforts are motivated by the outstanding properties of this class of materials in terms of stability, high absorption coefficient near the band edge and no significant health concerns compared to their halide counterparts. The approach followed here is to use stacked precursor layers and is adopted from other chalcogenide photovoltaic materials like the kesterites and chalcopyrites. The successful synthesis of BaZrS₃ from stacked layers of BaS and Zr and annealing at high temperatures (~1100 °C) with the addition of elemental sulfur is demonstrated. However, the film shows the presence of secondary phases and a flawed surface. As an alternative to this, BaS₃ could be used as precursor due to its low melting point of 554 °C. Previously, the fabrication of BaS₃ films was demonstrated, but in order to utilize them in the fabrication of BaZrS₃ thin films, their microstructure and processing are further improved in this work by reducing the synthesis temperature to 300 °C, resulting in a smoother surface. This work lays the groundwork for future research in the fabrication of chalcogenide perovskites utilizing stacked layers and BaS₃.