Abstract
•A comprehensive study of influence of Li, K and Be doping on structural modification, bandgap tuning and optical response of SrTiO3.•The inclusion of K, Li and Be doping at Sr site in SrTiO3 alter the band gap from 1.792 eV to 1.888 eV, 1.897 eV and 1.620 eV, respectively.•The refractive index increases by doping as 2.49–4.6.•The absorption edge shifted to lower energy with Be doping.•Electronic structure and optical properties are strongly correlated.
In the current work phase stability, band structure, and optoelectronic response of strontium titanate (STO) with doping of lithium (Li), potassium (K) and beryllium (Be) have been investigated in detail for possible application in semiconductor devices. The partial replacement of Sr-atoms with the Li-, K- and Be-atoms modify the structural parameters to a certain extent and remodeled the band gap of intrinsic STO with the occurrence of newly formed k-points. There is an increase in bandgap of pure STO with Li and K doping from 1.792 eV to 1.897 eV and to 1.888 eV, respectively. But in case of Be doping its value decreases to 1.620 eV. For pure and doped STO, the bandgap nature remains unchanged i.e. indirect bandgap. Several optical parameters are observed to be affected by the doping. For instance, the absorption edge is moved to low energy (0.32 eV-0.02 eV, red shift) for Be-doped STO. We have also observed an increase in static refractive index (2.49–4.6).