Exploration of Physical, Optical, and Electrical Properties of Mg-Doped CeO₂ Nanoparticles for Photovoltaic Device Applications

In this study, we synthesized magnesium-doped cerium oxide (Ce_1 – xMg_xO₂) Electron Transport layer material via a straightforward co-precipitation method, varying the Mg compositions. These variations yielded promising alterations in the physical, optical, and dielectric properties of Ce_1 – xMg_xO₂ nanoparticles. The hexagonal structure of the Ce_1 – xMg_xO₂ nanoparticles was confirmed using X-ray diffraction (XRD), while their morphology and surface characteristics (including topography and roughness) were examined via scanning electron microscopy (SEM). Ultraviolet-visible (UV–Vis) spectrophotometry was employed to investigate the optical and electrical properties. The optical analysis revealed an increase in transmittance within the visible spectrum, ranging from 89 to 98%, accompanied by decreases in reflectance and absorbance. Moreover, energy bandgap (E_g) was enhanced 3.578–3.864 eV, while the Urbach energy (E_U) diminished from 0.25–0.11 eV with varying Mg alignments. The augmentation in Mg substitution induced an growth in defect amount, consequently diminishing both DC and AC conductivity.