¹ Energy and Renewable Energies Technology Center, University of Technology-Iraq, Baghdad 10066, Iraq;

² Physics Department, College of Science, Mustansiriyah University, Baghdad 10052, Iraq

* Correspondence: ahmed_naji_abd@yahoo.com

Pulsed laser ablation in liquid was used to prepare cadmium oxide (CdO) nanoparticles, providing a clean, path-selective process for building high-purity nanostructures with highly uniform morphology. The morphology and structure of the synthesised CdO nanoparticles were determined by XRD, and AFM. The polycrystalline cubic rock-salt structure with an average crystallite size of about 20 nm was confirmed by XRD. The spherical, cluster-like, cubic assembly of the nanocomposites was confirmed by SEM, and the uniform, smooth thin-film surface was examined by AFM. Optical studies revealed strong UV absorption with a peak at 340 nm, and the estimated optical band gap was 2.7 eV. A photo-detector was created by depositing CdO on porous silicon, which showed a wavelength-dependent photoresponse, with enhanced responsivity in the near-infrared region, achieving a maximum detectivity of 3.0 × 10⁷ Jones at 950 nm. Additional FTIR and PL spectroscopy were performed for complementary chemical and luminescence characterisation. The findings demonstrate the potential of laser-synthesised CdO as a candidate material for plasmonic-compatible optoelectronic devices, especially for photodetection and NIR applications.