Exploring the Impact of Layer Thickness on the Structural, Optical, and Optoelectrical Properties of n-type Li2ZnO2 Films for Fabricating a New Window Layer

This work presents a study on lithium zinc oxide (Li2ZnO2) films deposited using spray pyrolysis. X-ray diffraction patterns revealed the polycrystalline state of the inspected samples. The optical investigation of the Li2ZnO2 layers indicated that the Li2ZnO2 films reported higher transmittance values of more than 80%, which lowered as the thickness rose. Also, enlarging the thickness boosted the refractive index of the Li2ZnO2 layers from 1.85 to 2.95. Meanwhile, the analysis of the energy gap (Eg) of the Li2ZnO2 layers confirms the presence of a direct energy gap (Eg) that falls from 4.12 to 2.68 eV by growing the film thickness. The investigation of Li2ZnO2 layers’ optoelectrical properties indicates that increasing thickness improves dielectric constants, optoelectrical performance, and optical conductivity. On the other hand, expanding the thickness boosted the nonlinear optical indices of the Li2ZnO2 layers. The n-type semiconductor behaviour of Li2ZnO2 layers was verified using the hot-probe technique. This research underscores the importance of Li2ZnO2 layers as a viable window layer for thin film solar cells and a strong contender in optoelectronic applications, advancing these disciplines.