Synthesis of Y₂O₃ Nanoparticles in Water and Ethanol by Pulsed Laser Ablation for Y₂O₃/n-Si Heterojunction Photodetectors

Abstract

Nanoparticles (NPs), nanotubes, rods, and sheets made of rare earth metals have recently become the material of choice for many device applications. This study aims to synthesise Y₂O₃ nanoparticles using the laser ablation technique in two different liquid media (deionized water and ethanol) and investigate their structural, morphological, optical, and chemical properties, as well as to evaluate the performance of Ag/Y₂O₃/n-Si/Ag heterojunction UV photo-detectors based on the prepared nanoparticles. Studies have been conducted on the structural, morphological, optical, and chemical characteristics of Yttrium oxide. XRD results verify the production of a polycrystalline Y₂O₃ film have cubic crystalline phase with crystallite sizes of 10.52 nm for Y₂O₃ in ethanol and 42.53 nm for Y₂O₃ in water.  The SEM results of Y₂O₃ in ethanol show brittle and porous particles of different sizes ranging from 19.79 nm to 95 nm, while Y₂O₃ in water, the particles were of different shapes with some agglomerates with a particle size range of 40.27 nm to 3 μm. In the AFM image, the Y₂O₃  film's grains measured 49.25 nm in size for case ethanol, whereas in water, particles measured 52.97 nm. The energy gap of Y₂O₃ NPs (ethanol and water, respectively) was 4.9 eV and 4.8 eV. The bond Y–O stretching mode of the Y₂O₃ structure is responsible for the high intensity peaks detected by FTIR, which are concentrated around 500-696 cm−1. For Y₂O₃ in ethanol and water, the photo-detector's responsivity at the short wavelength region (350-400nm) was 0.16 and 0.17 A/W, respectively. However, for Y₂O₃ in ethanol and water, the photo-detector's responsivity at 850 nm was 0.42 nm and 0.51 A/W, respectively. The Y₂O₃ /n-Si heterojunction photo-detector's specific detectivity D* was determined to be 6.0×1012 and 7.3×1012 Jones, with corresponding quantum efficiencies of 59% and 62% at 350 nm for in case ethanol and water, respectively. It is recommended that the synthesis of Y₂O₃ by the method employed in this experiment would be beneficial for fabricating Y₂O₃ nanostructures with good electrical and optical properties to be used in UV optoelectronic devices.