Laser Fabrication of ZnO Thin Films and Nanostructures: A Critical Review of Process Parameters and Environmental Effects

ZnO is a popular topic in the materials research field due to its enormous bandgap, multifunctional properties and high exciton binding energy. Two methods that employ laser pulses to produce NPs and thin films are pulsed laser ablation in liquid (PLAL) and pulsed laser deposition (PLD). Recently, PLAL and PLD have been subjected to substantial investigation. This study critically evaluates current experimental and theoretical investigations that focus on the interactions of major process factors. The first part presents an introduction of the fundamental concepts of pulsed laser nanocolloid production. The synthesis of NPs by PLAL is mainly influenced by the following factors: focal length, liquid environment, laser wavelength, ablation duration, fluence, laser pulse repetition rate, and pulse number. The second part elaborated on the experimental and theoretical aspects of PLD techniques for producing ZnO NPs and films. The fundamental concepts of PLD in vacuum technology include ablation and the creation of a plasma plume. many deposition methods and parameters that affect the film's properties during the pure ZnO deposition process, such as pulse repetition rate, post-growth annealing, substrate temperature, deposition time, laser fluence, and oxygen pressure. These factors impact nucleation and crystallization during the deposition process. Results indicate a correlation between shorter pulses and shorter wavelengths and smaller, more monodisperse nanoparticles in PLAL. Adatom mobility, texture, and defect density in PLD films are influenced by substrate temperature, background gas pressure, and laser fluence, respectively. The analysis closes with actionable process-property mappings and experimental suggestions for the consistent manufacturing of ZnO nanostructures for device applications.