Assessing the optoelectronic performance of d-orbital doped cubic HfO2: The case of W, Nb, and Mo

This contribution provides an atomistic understanding into the impact of W, Nb, and Mo co substitution at Hf-site of cubic HfO2 lattice to produce Hf(1_x)TMxO(2) system at x = 25%. The calculations have been performed under the framework of density functional theory supported by Habbured parameter (DFT+U). Structural analysis demonstrates that the recorded lattice constants is in good coherence with the previously published results. For the lattice parameters, contraction by 1.33% comparing with the host system has been reported. Furthermore, the doping effect of TM on the band gap leads to its reduction in the resulting Hf0.75TM0.25O2 configurations. The partial density of states (PDOS) indicate that hybridization through localized electronic energy states from TM-5 and 6 d orbitals and O-2 p orbital have participated in narrowing the band gap. Population analysis displays that Hf0.75TM0.25O2 compounds revealed ionic and covalent behavior for Hf-O and TM-O bonds, respectively. The optical investigation portrays that Hf0.75TM0.25O2 systems would absorb a broad range of ultra violet (UV) electromagnetic waves which hence consider them as suitable candidates in optoelectronic memristors industries. Optical analysis also revealed a rise in the optical conductivity and absorption in higher photon energy extent. These compounds are suitable for photovoltaic and other optoelectronic applications. The zero values of the optical conductivity for the simulated systems in a broad range of electromagnetic waves confirm the impossibility of the electronic charge transfer to be occurred through the systems and hence preventing the leakage current which is not preferred in optoelectronic devices such as metal oxide semiconductor field effect transistors (MOSFETs).

Automated summary

This contribution provides an atomistic understanding of the impact of W, Nb, and Mo co-substitution at the Hf-site of the cubic HfO2 lattice to produce the Hf(1_x)TMxO(2) system at x = 25%. The calculations were performed using density functional theory (DFT) supported by Habbured parameter (DFT+U). The results show that the lattice constants are consistent with previous studies, with a contraction of 1.33% compared to the host system. The doping effect of TM on the band gap leads to its reduction in the resulting Hf0.75TM0.25O2 configurations. Optical analysis reveals that Hf0.75TM0.25O2 systems can absorb a broad range of UV electromagnetic waves, making them suitable candidates for optoelectronic devices.