Exploration of manganese on structural, morphological and optical properties of MnxIn2S3+x (0 ≤ x ≤ 1.0) nanoparticles

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 Mn_xIn₂S_3+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 (E_g) range of Mn_xIn₂S_3+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.