Numerical Study of Au and Ag Nanoparticles for Enhanced Optoelectronic and Photocatalytic Performance of LaMnO ₃

Abstract

ABSTRACT Functional ABO 3 perovskite oxides are a highly diverse and active field of research at the interface between chemistry and solid‐state physics. These materials have remarkable optoelectronic and photocatalytic properties, which make them suitable for use in advanced technological fields. In particular, they can improve the efficiency of optoelectronic devices and facilitate cutting‐edge photocatalytic reactions, such as the degradation of pollutants, CO 2 reduction, and hydrogen production. The assembly of plasmonic nanoparticles (NPs), such as gold (Au) or silver (Ag), with perovskite oxides significantly enhances the performance of the latter thanks to surface plasmon resonance (SPR), which is a fundamental property of noble metal NPs. This work focuses on studying the improvement of the optoelectronic properties of LaMnO 3 perovskite (lanthanum and manganese [III] oxide) through the integration of spherical (S) and hollow (H) Au and Ag NPs (SNPs, HNPs). First, density functional theory was used to determine the optical properties of the LaMnO 3 perovskite crystal structure. Second, the finite element method was used to analyze the optoelectronic and plasmonic properties of the LaMnO 3 –NPs nanocomposite. Four types of NPs were considered, namely, two solid spheres made of Au and Ag (AuSNPs, AgSNPs) and two hollow spheres (AuHNPs and AgHNPs), for which the SPR characteristics were determined as a function of parameters such as the volume fraction and the size of the nanometric cavity. The near‐field enhancement effect induced by the presence of these NPs in the LaMnO 3 matrix is studied by calculating the field amplification factor. Subsequently, the optimization of light absorption after the introduction of these plasmonic NPs is evaluated by determining the associated optical parameters, such as transmittance and absorbance. Finally, the bandgap energy of the nanocomposite is calculated from the absorption coefficient using the Tauc plot method. The results of this study demonstrate that the incorporation of spherical and hollow Au and Ag NPs significantly improves the absorption performance of LaMnO 3 perovskite. In addition, the addition of these NPs leads to a reduction in the bandgap energy of the LaMnO 3 semiconductor. These improvements in the optoelectronic properties of LaMnO 3 perovskite broaden its response spectrum, which is particularly advantageous for applications in photocatalysis and advanced optoelectronic devices.