Surface plasmon enhanced green light emitting diodes with silver nanorod arrays embedded in p-GaN

摘要

We demonstrated surface-plasmon (SP) enhanced green light-emitting diodes (LEDs). Three types of Ag nanorod arrays with a minimum distance between the quantum well (QW) and Ag of 20, 40, and 55 nm respectively were fabricated on' p-GaN layer. Photoluminescence measurements showed ～175% emission enhancement for the 20 nm spacing while almost no enhancement for the 55 nm spacing. Simulation result showed that a localized surface plasmon resonance (LSPR) at a wavelength of ～500 nm generated by Ag nanorod arrays induced InGaN/GaN QW and SP coupling. However, the electrical field of the LSPR generated by Ag nanorods only spread ～40nm in the vertical direction in GaN. This simulation result well explains the observation of SP-QW coupling emission enhancement for 20 nm spacing between Ag and QW, and the lack of enhancement for the 55 nm spacing samples.