First principles study of co-doping exploration of (Ba, Ra) on bulk like ZnS and ZnO for emerging applications of optoelectronic

This unique research investigates the co-doping effects of Ba and Ra on the structural, electronic, optical, thermodynamics and mechanical response of Bulk-like ZnO and ZnS based 3d-dimensional crystal structures. Using Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) and generalized gradient approximation with norm-converging pseudopotential approach in the density functional theory. The (Ba, Ra)-doped ZnO (BZO, RZO) and (Ba, Ra)-doped ZnS (BZS, RZS) models with doping concentrations are assembled to systematically declare the impact of doping concentration (x) on the optoelectronic performance of ZnO and ZnS. Additionally, optoelectronic excellency, such as band gap tuning, electronic conductivity, reflectivity, transmittance and absorption as well as mechanical stability have been computed. It is observed that after (Ba, Ra)-doping and its impact on crystal vacancy can influence band levels hence decreasing the band gap of the 3d ZnO and ZnS. As a consequence, the decreased band gap is attributed to the enhanced absorption in the visible region and explores wide the applicable range of ZnS and ZnO. Compared to the ZnO, it is revealed that (BZO RZO) and (BZS, RZS) are remarkably much softer with 18% stiffness and 33% ultimate strengths computed respectively. The excess specific heat (C_V) and enthalpy of mixing (H_m) as well as phonon responses resulting from the concentration x are estimated to investigate the thermodynamic stability responses of the Zn_0.97Ba_0.03O, Zn_0.97Ra_0.03O and Zn_0.97Ba_0.03S, Zn_0.97Ra_0.03S. Finally, the absorption and conductivity as well as optical performance of BZO, RZO and BZS, RZS materials are found to be extremely sensitive to the dopant concentrations. The obtained theoretical results indicate that the doped BZO, RZO and BZS, RZS materials can be proven as potential promising candidates for optoelectronic applications.