Experimental investigation of laser annealing effects on the optoelectronic performance of ITO/Ag/ITO electrodes prepared by sputtering

Abstract

This study integrated numerical methods and experimental observations to explore the mechanisms with which UV laser annealing (LA) impacts the performance of ITO/Ag/ITO electrodes. Optimization of the electrode structure and sputtering parameters using the Taguchi method increased the Haacke index from 18.12 × 10⁻³ to 19.17 × 10⁻³ Ω⁻¹. LA experiments further demonstrated that carefully controlled energy densities noticeably improved electrode performance, achieving a peak Haacke index of 32.10 × 10⁻³ Ω⁻¹. Conversely, excessive energy densities caused damage to the silver film, induced nanostructure formation, and triggered surface plasmon effects, leading to degraded optical properties and reduced optoelectronic performance. These morphological changes were confirmed by TEM analyses. Finite element simulations combined with machine learning analyses revealed that high LA energy densities increased the temperature of the silver film well above its recrystallization threshold, resulting in structural alterations within the silver layer and deteriorated optical properties. Conversely, moderate LA energy densities raised the temperature in the recovery range, effectively reducing defect density and enhancing electrical conductivity. Based on these results, this study concludes that the critical factor in laser annealing of multilayer electrodes is precise control of the annealing temperature to ensure the silver film undergoes recovery without obvious recrystallization, thereby optimizing its performance.