Optimization of La and Ce mixed metal oxide hybrid for enhanced photoresponse in UV–Visible photosensing applications
摘要
In this study, La2O3/CeO2 hybrid nanocomposites with varying La-to-Ce molar ratios (1:1, 1:2, and 1:3) were successfully synthesized via a simple co-precipitation method and evaluated for UV–visible photodetector applications. X-ray diffraction (XRD) analysis confirmed the formation of a crystalline hybrid structure between La2O3 and CeO2. Optical analysis showed a bandgap reduction from 3.82 eV (1:1 La2O3/CeO2) to 3.25 eV (1:2 La2O3/CeO2) and then slightly increasing to 3.52 eV (1:3). Textural analysis indicated a surface area increase from 42.3 m2/g (1:1 La2O3/CeO2) to 61.8 m2/g (1:2), followed by 54.5 m2/g in 1:3 La2O3/CeO2 composite. The photosensing results demonstrated that 1:2 La2O3/CeO2 composite had the maximum photocurrent (0.231 μA), responsivity (4.62 × 10⁻⁶ A/W) and detectivity (4.08 × 107 Jones), as well as quick response and recovery periods (1.2 s and 1.4 s, respectively). In comparison, 1:1 La2O3/CeO2 and 1:3 La2O3/CeO2 showed reasonable values (photocurrent: 0.128 and 0.179 μA, responsivity: 2.56 × 10-6 and 3.58 × 10-6 A/W, detectivity: 2.26 × 107 and 3.16 × 107 Jones, respectively). These findings demonstrate that the optimized LC-2 composition successfully balances light absorption, surface area, and interfacial charge separation, making it attractive candidates for the next-generation UV–Visible photodetector applications.