Open Access

ARTICLE

Laser-Ablated CdS and Ag₂O Nanomaterials for High-Sensitivity Photodetectors

Hameed H. Ahmed¹, Thaer A. Mezher^2,*, Marwan R. Rashid³

1 Department of Mechanics Engineering, College of Al-Shirgat Engineering, Tikrit University, Tikrit, 34001, Iraq
2 Directorate General of Education in Diyala, Baqubah, 32001, Iraq
3 Department of Physics, College of Education for Pure Sciences, University of Diyala, Baqubah, 32001, Iraq

* Corresponding Author: Thaer A. Mezher. Email:

Chalcogenide Letters 2025, 22(12), 1055-1066. https://doi.org/10.15251/CL.2025.2212.1055

Accepted 28 September 2025; Issue published 10 December 2025

Abstract

Laser ablation in liquids (LAL), a hygienic and effective method for creating high-purity nanomaterials, was used in this study to create cadmium sulfide (CdS) and silver oxide (Ag₂O) nanoparticles. The sputtering process was used to deposit the produced nanomaterials on porous silicon (PSi) substrates, and a number of assays were used to examine the samples’ structural, optical, and electrical characteristics. The CdS sample had a hexagonal crystal structure, according to X-ray diffraction (XRD) data, whereas the AgO sample had a cubic structure. The diameters of the nanoparticles in the two samples ranged from 22.64 nm for CdS to 32.69 nm for AgO. The CdS sample had almost normal spherical particles, according to scanning electron microscopy (SEM) pictures, whereas the AgO sample had cluster formations. The CdS sample’s surface roughness was 4.78 nm, while the AgO sample’s was 9.14 nm, according to atomic energy microscopy (AFM) photographs. The optical energy gap (Eg) for the CdS and AgO samples, as determined by UV-Vis spectroscopic tests, was 6.4 eV and 5.52 eV, respectively. This indicates a distinct change in characteristics brought about by nanoscale size and quantum effects. Analysis was done on optical constants like the dielectric constant, optical conductivity, extinction coefficient, and refractive index. Additionally, the Ag/AgO/CdS/PSi thin film’s photovoltaic characteristics were examined. With a particular sensitivity of (D* = 1.2 × 1011 Jones) and a quantum efficiency of (Q ≈ 89%), the composite demonstrated a wide spectrum response from 350 to 1050 nm. These findings demonstrate that the Ag/AgO/CdS/PSi thin film has exceptional qualities that make it a promising option for photovoltaic and photodetector applications, especially in the visible and near-infrared spectrum.

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