Optical and structural characterization of SILAR-coated Mn-doped ZnS films for LEDs

Abstract

This study explores the structural and optical properties of Zn_1-xMn_xS thin films, with varying Mn content (x) between 0 and 0.07. These films are meticulously fabricated on glass substrates using the successive ionic layer adsorption and reaction method. The results confirm the polycrystalline nature of these samples, revealing their crystallization in a cubic phase with the Fm-3 m space group, and providing insights into their fundamental structural makeup. Notably, these films possess a nanocrystalline character, with grain sizes ranging from 2.7 to 2.1 nm, indicating a finely textured structure at the nanoscale. The optical band gap energy, determined using Tauc's plot method, ranges from 3.53 to 3.56 eV. In the realm of optics, the study unveils that the incorporation of manganese dopant has minimal impact on the optical band gap energy, showing only minor fluctuations. This makes Mn-doped ZnS a promising material for optoelectronic applications due to its minimal absorption losses in the visible spectrum. Additionally, the research uncovers vital details about defect levels, including cation and anion vacancies, obtained through photoluminescence measurements. These defects have the potential to significantly influence the material’s electronic properties and its suitability for various applications. The utilization of a chromaticity diagram in the study elucidates the promising potential of this engineered material within the semiconductor sector, especially in the context of light-emitting diode (LED) technology, where its efficient light-emitting properties are poised to make a substantial contribution.