Photodetector Fabrication and Characterization of Gold-Cerium Oxide Nanoparticles for Next-Generation High-Efficiency Devices

Abstract The various uses of nanocomposite in environment monitoring, medical devices and optoelectronic appliances have pushed for the synthesis of advanced nanocomposites for high photodetector performance. The objective of this research is to synthesize and investigate nanocomposites made of gold and cerium oxide (Au-CeO 2 ) to improve the performance of photodetectors. The synthesis was conducted using a Q-switched Nd:YAG laser (1064 nm, 300 mJ, 6 Hz) in both deionised and distilled water with 500 laser pulses. The synthesised particles have cubic crystalline structure and are in the nanoscale as supported by the results from XRD. UV-visible, the spectra of Au-CeO 2 composite has shown a decrease in the optical band gap leading to the better light absorption as confirmed through photoluminescence. At 50 kV, FESEM analysis revealed spherical nanoparticles with a size range of 15-29 nm and core-shell structure uniform throughout the samples. Current voltage (I-V) characterizations confirmed Ohmic conduction and improved photocurrent under light conditioning. A 95% improvement in spectral responsivity and an increase in quantum efficiency for the photodetector with the gold nanoparticles at 550 nm was observed and explained as to why the addition of gold nanoparticles aid in better photodetector performance. These results suggest that the Au-CeO 2 nanocomposites can be used in next generation photodetectors due to its cost effectiveness and high efficiency optoelectronic, catalytic characteristic in optoelectronics, catalysis and other areas. These investigations could be furthered by future studies on the application of this fibre fabrication method on a larger scale and to other uses in electronic products.