Under atmospheric conditions, silver nanowires were prepared via an (NH₄)₂CO₃-mediated polyol process rather than the normally used metal salt-mediated polyol processes in order to improve the purity. The results revealed that the obtained silver nanowires had rounded ends rather than the conventionally believed {111} crystal planes. A growth mechanism was firstly proposed, in which a dynamic reversible deposition and dissolution process of Ag atoms occurred at the curved ends of the silver nanowires. The proposed mechanism could explain the effects of the titration rate, PVP and (NH₄)₂CO₃ concentrations on the growth the of silver nanowires. Both melting and dissolution of Ag atoms contributed to the arcing of twin boundaries in multiply-twinned particles. The multiply-twinned particles with arcing twin boundaries finally grew into silver nanowires with rounded end shapes and higher aspect ratios. Lattice fringes of the twin structure were observed for the first time at the curved ends of the silver nanowires, and the addition of (NH₄)₂CO₃ was found to facilitate the growth of the silver nanowires.

High operating temperatures generally degrade the luminous performance of color converters used in high-power, laser-driven white lighting systems. This study demonstrates that the operating temperature of LuAG:Ce films can be significantly reduced, particularly under high-power laser excitation near the saturation threshold. This improvement was achieved by enhancing the crystallinity and increasing the Ce³⁺ content in LuAG:Ce films. LuAG:Ce films, approximately 22.17 μm in thickness, were deposited on sapphire substrates via spray pyrolysis techniques. The crystallinity was controlled by the annealing temperature, while the Ce³⁺ content was regulated by the annealing atmosphere. Air-annealed films with a crystallinity of 87.4% exhibited a remarkable 95.6 °C decrease in operating temperature compared to those with a crystallinity of 75.5% under 18 W/mm² blue laser excitation. Additionally, the incorporation of a higher Ce³⁺ content through CO-annealing led to a further reduction in operating temperature. By lowering the operating temperature, LuAG:Ce films on sapphire substrates exhibit enhanced luminous performance and thermal stability under prolonged high-power laser excitation, which could inspire the design and development of advanced color converters for laser lighting applications.

LuAG:Ce (Lu₃Al₅O₁₂:Ce) is one of the most important color converters in white lighting industry. Especially, LuAG:Ce film attracts more attention due to the outstanding advantages, such as the efficient heat dissipation, the saving of rare earth, and so on. Here, LuAG:Ce film on sapphire was successfully prepared by the ultrasonic spray pyrolysis process. The phase, microstructure and photoluminescence of LuAG:Ce films were investigated. LuAG:Ce films had a thickness of around 5 μm, which were well crystallized at 1000 °C in air atmosphere to form the typical garnet structure. Under the protection of CO atmosphere, increasing the annealing temperature greatly enhanced the photoluminescence performance. After annealing at 1500 °C for 5 h in CO atmosphere, 3.0 mol.% Ce³⁺ doped LuAG:Ce film exhibited the highest emission and excitation intensity. The emission intensity of 3.0 mol.% Ce³⁺ doped LuAG:Ce film annealed at 1500 °C in CO atmosphere increased up to five times, when compared with the best LuAG:Ce film annealed at 1000 °C in air atmosphere. The effects of Ce³⁺ doping concentration on the photoluminescence were also examined. As the Ce³⁺ doping concentration increased from 0.2 mol.% to 7.0 mol.%, the color of LuAG:Ce films changed from yellowish green to greenish yellow. When coupling the 3.0 mol.% Ce³⁺ doped LuAG:Ce film with a 0.5 W 450 nm blue laser, the formed device successfully emitted white light.