Abstract

Controlling the morphology and optical properties of nanoparticles is crucial for advancing the development of various nanomaterials based functional devices, such as optoelectronic, biomedical and energy storage devices. The current work investigates structural, morphological and optical properties of MnxIn2S3+x (0 ? x ? 1.0) nanoparticles (NPs) synthesized by hot-injection method. Oleic acid and octadecene served as capping agents and non-coordinating solvents. The incorporation of Mn2+ ions was evident from the color change from yellow (In2S3) to dark brown (MnIn2S4). The structural, morphological and optical properties of nanomaterials were characterized using various spectroscopic techniques, like XRD, HR-TEM, XPS, UV-DRS and PL analysis. XRD analysis confirms the formation of cubic In2S3 and MnIn2S4 crystal structures. XPS analysis verified the electronic oxidation states of elements, which are present in MnIn2S4 NPs. In2S3 (x = 0), and MnIn2S4 (x = 1.0) nanoparticles exhibits spherical, and flake-like morphologies, which are confirmed by HR-TEM images. UV–vis DRS revealed a blue-shifts with increasing ‘x’ concentration from 0 to 1.0. The optical band gap (Eg) range of MnxIn2S3+x (0 ? x ? 1.0) was found in the range 2.18 and 2.82 eV by Kubelka- Munk plot. In addition, PL emissions shows concentration-dependent emissions with strong broad PL bands centered at 575, 490, and 475 nm. Finally, the luminescent properties of synthesized MnIn2S4 nanomaterial holds significant importance for investigating the potential applications for optoelectronic, bioimaging and energy storage devices. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.