OICC Press International Nano Letters 2228-5326 15 4 2025 12 30 Effect of Pulsed Laser Irradiation on Perovskite/TiO2 Nanoparticles 10.57647/inl.2025.1504.16 EN Nahid Ghazyani Faculty of Physics, Kharazmi University, Tehran, Iran https://orcid.org/0009-0005-5961-2954 Vahid Kamrani Pouya Department of Materials and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran Journal Article 2025 12 30 Perovskite layers are key nanoscale absorbers in a wide range of optoelectronic devices, driving intense research into their deposition control, crystallization kinetics, and interfacial nanoengineering. In this work, we investigate the effects of nanosecond-pulsed Nd:YVO4 laser irradiation (355 nm) on the structural and optical properties of perovskite layers integrated with TiO2 nanoparticles. Nanoscale modifications induced by laser processing are systematically analyzed through optical transmission, photoluminescence (PL), surface morphology, and elemental composition measurements. The results reveal laser fluence as a decisive parameter: Low fluence deteriorates optoelectronic performance by forming a defective surface dead layer via increased nanoscale roughness, whereas higher fluence enhances optical transmittance through controlled nanoscale ablation and film thinning. Moreover, the incorporation of a mesoporous TiO2 nanoparticle scaffold plays a critical role in maintaining bandgap stability during laser exposure, underscoring its protective function against localized thermal decomposition. These findings demonstrate that laser-matter interactions at the nanoscale can be precisely tuned to engineer perovskite layers for targeted optoelectronic device applications.