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In this study, the properties of the porous silicon (PS) photodetector were improved by depositing Au@In2O3 (core-shell) nanoparticles on the surface of PS. The Au@In2O3 NPs were prepared using the pulsed laser ablation in liquid (PLAL) technique at different laser energies of 500, 700, and 900 mJ, using a Nd:YAG laser with a wavelength of 1064 nm. The PS was prepared using the electrochemical etching (ECE) method, with an etching current density of 20 mA/cm2, an etching time of 15 min, and a hydrofluoric acid concentration of 25%. Structural, morphological, optical, and electrical measurements of the PS, Au@In2O3 NPs, and Au@In2O3 NPs/PS were conducted using the X-ray diffraction (XRD) test, field-emission scanning electron microscopy (FE-SEM) analysis, photoluminescence (PL), and UV-vis spectroscopy showed the highest peak of absorbance at 327–385 nm, and the photoluminescence (PL) peak of Au@In2O3 NPs was in the visible range show broad band and splitting for 399.5 nm for In2O3 NPs and 469 nm for Au NPs, while the PS peak was at about 561.8 nm. As a result, the photodetectors device system exhibited high responsivity (Rλ) and quantum efficiency in the visible area, the higher responsivity of the Au@In2O3 NPs/PS photodetector was measured as 0.1450 A/W for specimens prepared at a laser energy of 500 mJ/pulse. [ABSTRACT FROM AUTHOR]

Gold-titanium dioxide nanoparticles (Au-TiO2 NPs) were synthesized via pulsed Nd:YAG laser ablation in the CTAB under the influence of an external magnetic field produced. Scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Vis spectroscopy, and transmission electron microscopy (TEM) have been utilized in order to analyze Au-TiO2 NPs. The XRD pattern related to Au-TiO2 NPs indicated that they have been polycrystalline and the specimens Au-TiO2 were nanocrystalline. In the case when applying a magnetic field, spherical NPs are generated, particle agglomeration is reduced, and particle size declines from 31 to 25 nm, according to SEM. Following ablation with a magnetic field, the optical energy gap of Au-TiO2 NPs increased from 3.5 to 3.7 eV. With current density–voltage (J-V) measurements, the electrical parameters of Al/Au-TiO2/PS/Si/Al heterojunction, including the barrier height (ΦB) and ideal factor (n), were indicated. The efficiency regarding Au-TiO2/PS photodetectors has been enhanced over various wavelengths, quantum efficiency (QE) of Au-TiO2/PS photodetectors has been reduced after adding a magnetic field during the process of ablation. [ABSTRACT FROM AUTHOR]