Enhancements of emission rates and efficiencies by surface plasmon coupling

Surface plasmon (SP) coupling technique was applied to several InGaN/GaN-based single and multiple quantum wells (QWs) which have various emission wavelengths to understand detail mechanism and consider the possibility of plasmonic light-emitting diodes (LEDs). The coupling efficiencies from exciton to SP and from SP to photon were estimated by the time-resolved photoluminescence (TRPL) measurements. We found that the SP enhanced internal quantum efficiencies (IQEs) of emission reached almost 100% at the best matched wavelength. This should be applicable to super bright LEDs at any wavelength by optimizing the best SP coupling condition. Possible device structures of plasmonic LEDs were also proposed and discussed. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)