Practicable alleviation of efficiency droop effect using surface plasmon coupling in GaN-based light emitting diodes

摘要

We studied the practicable alleviation of efficiency droop effect in GaN-based light emitting diodes (LEDs) with surface plasmon (SP) coupling. Our approach is based on a simple ABC model which is extended by a Purcell factor that relates the SP coupling rate to the radiative recombination rate based on Fermi's golden rule. Purcell factors as small as two are found to be sufficient to obtain a low efficiency droop of only 5.2% at a current density of 200 A/cm~2. It is shown that a high probability of photon extraction from the SP modes is required for enhanced light output power. SP coupling is more beneficial to improve LED performance within the "green-yellow gap" suffering from low luminescence efficiency (less than 20%).