Enhancing the light emission efficiency of LEDs based on array of Ag nanohollow cylinders and SPR theory

The internal spontaneous emission and external light extraction efficiency have been key issues in the research on LEDs incorporating metal nanoparticles , particularly in terms of transmittance, which presents a series of challenges and less-than-satisfactory outcomes. In this study, we address this issue by proposing a new approach that combines periodic structures with metal surface plasmons . Specifically, we embed an array of Ag nanohollow cylinders above the quantum wells of the LED structure and investigate its impact on the light emission characteristics using the finite-difference time-domain (FDTD) method. By varying the height and radius ratio of the hollow cylinders, the internal spontaneous emission and external light extraction efficiency of the LED can be significantly enhanced. At h = 12 nm, r/R = 1:3, the internal spontaneous emission rate is enhanced by a factor of 3.64. Under the condition of r/R = 1:3, the internal quantum efficiency reaches 90% for h values of 3 nm, 6 nm, 9 nm, 12 nm, and 15 nm. The transmittance increases from 0.26 to 0.44 at h = 3 nm, r/R = 1:3, and the enhancement factor of light extraction efficiency also reaches 1.73. These research findings reveal that embedding a nano Ag hollow cylinder array structure above the active layer can significantly enhance the light emission efficiency of LEDs. The introduction of this structure effectively utilizes the surface plasmon resonance effects of metal nanoparticles and their coupling with the active layer. This provides an important theoretical reference for further improvement and optimization of metal nanostructure designs.