Structural, optical investigations of Zn0.98-xSn0.02MnxS (x ≤0.04) quantum dots for optoelectronic applications

Incorporation of transition elements (such as Mn, Sn, Mg, Cu, Ni, Co, Cr) as a dopant on quantum dots is an interesting technique to influence the structural and optical properties of the target materials. The quantum confinement effect, band gap tailoring, shifting of photoluminescence peaks have been observed as the cause of the doping process. Herein, Sn-doped (2 wt%) ZnS quantum dots and Sn, Mn co-doped (0−4 wt%) ZnS quantum dots were synthesized by the coprecipitation method. The Transmission Electron Microscope image and Debye-Scherrer formula for XRD results were employed to estimate the average particle size of the samples. Particle size was reduced when increase the doping concentration. The particle size was ranged to ∼ 3 nm. The morphological, elemental and optical properties were explored using characterization techniques such as Scanning Electron Microscope, Fourier Transform Infrared spectroscopy, UV–vis optical study and photoluminescence spectroscopy. According to the results obtained from UV–vis optical absorption, A high transmittance was exhibited by the 2 wt% Sn- doped Mn:ZnS nanoparticles. The PL peaks were observed in the UV region and red light range. A strong red emission with high intensity was obtained for 2 wt% Sn- doped Mn:ZnS nanoparticles. This emission was discussed in terms of d–d state transition in Mn2+ and Sn2+ ions.