Investigation the optical and structural properties of Mn-doped Sb2S3 nanocrystals embedded in host glass

The search for earth-abundant and non-toxic elements is essential for the manufacture of sustainable optical devices. In this context, dilute magnetic semiconductor (DMS) xMn-doped Sb2S3 nanocrystals (NCs) embedded in host glass were synthesized by the fusion method. Differential Thermal Analysis shows evidence of Sb2S3 phase crystallization peak and changes in glass transition and crystallization temperatures of the host glass with the presence of xMn-doped Sb2S3 NCs. Transmission electron microscopy images show the formation of xMn-doped Sb2S3 NCs with increasing size (2.1 to 3.8 nm) as a function of concentration (x = 0.00 to 0.40), respectively. X-ray diffraction measurements reinforced the evidence for the orthorhombic structure of xMn-doped Sb2S3 NCs embedded in glass. Energy dispersive X-ray spectroscopy analyses confirm the S, Sb and Mn precursor elements of DMS NCs. Atomic and magnetic force microscopy measurements show the magnetic contrast patterns resulting from the incorporation of Mn atoms into the Sb2S3 structure. The electronic paramagnetic resonance spectrum confirms the presence of Mn2+ ions (3d5) located in the crystal field of the Sb2S3 semiconductor due to six hyperfine transitions. The redshift of the Raman vibrational mode (1Ag) with increasing xMn concentration gives strong evidence for the presence of Mn2+ ions in sulfur vacancies (VS) in the Sb2S3 unit cell. Optical absorption and photoluminescence (PL) spectroscopy measurements for xMn-doped Sb2S3 NCs show the subtle tunable redshift of the band gap and excitonic recombination in the green-red region, with increasing x concentration. PL confirms that dopant Mn2+ ions fill VS2 that are dominant in Sb2S3. Therefore, the position of the energy states after the increasing concentration of Mn2+ dopant ions gives rise to insight into luminescence for future research scenarios and applications involving sustainable DMS NCs.