A DFT study of (La2O3)n clusters and effect of Ba, Y and Hf doping for their optoelectronic applications.

$ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n (n=1-5) clusters have been computationally studied using DFT and TDDFT with B3LYP functional under hybrid GGA approximation and LANL2DZ basis set. The doping effect of various elements like Ba, Y and Hf on the structural, electronic and non-linear optical (NLO) properties of $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters has been studied for finding their optoelectronic applications. Different optimised geometries of $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n and Ba, Y and Hf doped $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters have been obtained. HOMO-LUMO gap $ (\Delta \mathcal {E}) $ (Δ E) and chemical hardness (τ) of $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters decreases significantly with doping of Ba, Y and Hf atoms making these clusters very reactive. Refractive index and the absorption in UV–VIS region of electromagnetic spectra of Ba, Y and Hf doped $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters increases as compared to $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters making these clusters suitable to be used as additives in the manufacturing of various types of glasses. Also, dielectric constant (ϵ) of Ba, Y and Hf doped $ ({\rm La}_2 {\rm O}_3)_{\rm n} $ (La 2 O 3) n clusters increases finding their applications to be used in the oxide layer of MOSFETs. [ABSTRACT FROM AUTHOR]