Hetero-valent cations-doped zinc stannate nanoparticles for optoelectronic and dielectric applications

The continuous development in the field of the electronics industry has increased the demand for optoelectronic and dielectric substrate materials. Herein, ZnSnO3 (ZTO) and Mxn: Zn1-xSnO3 (Ca/Mn-ZTO and Cr/Ca/Mn-doped ZTO) nanopowders were prepared via a simple and low-cost coprecipitation method. The structural and functional characteristics were studied using XRD, FESEM, EDS, FTIR, and XPS techniques. The obtained results resembled rhombohedral crystal structure for all samples and gradual reduction was observed in the values of particle size and diffraction angles in the doped ZTO samples. FTIR results showed that multi-doping of ZTO with Ca2+/Mn2+ or Cr3+/Ca2+/Mn2+ causes a shift to higher frequency values of the tetrahedral and octahedral absorption bands indicating the impact of dopant cations on changing the crystal field in the lattice due to the induced strain with larger number of hetero-valent cations. Pristine ZTO particles appeared as agglomerated, dense, and compact blocks, while Cr/Ca/Mn-doped ZTO particles demonstrated larger homogeneity and less agglomeration having a spherical-like shape. The calculated band gap values for pristine ZTO, Ca/Mn-doped ZTO, and Cr/Ca/Mn-doped ZTO nanomaterials are about 2.27, 1.8, and 1.68 eV, respectively. Pure ZTO material possessed high dielectric constant which decreased by increasing the number of doping elements as a result of increasing the electronic conductivity. Moreover, Cr/Ca/Mn-doped ZTO showed the lowest ε′, ε'' and tanδ values in comparison with pristine and Ca/Mn-doped ZTO materials. Consequently, ternary cations doped ZTO materials displayed the best optical and electrical responses for optoelectronic, semiconductors, and electronic devices.