Enhanced and partially polarized output of a light-emitting diode with its InGaN/GaN quantum well coupled with surface plasmons on a metal grating

The enhanced and partially polarized output of a green light-emitting diode (LED), in which its InGaN/GaN quantum well (QW) couples with surface plasmons (SPs) on a surface Ag grating structure, is demonstrated. Compared with a LED sample without (flat) Ag coating, the total output intensity of an LED of SP-QW coupling can be enhanced by ∼59% (∼200)% when the grating period and groove depth are 500 and 30 nm, respectively. Also, a bottom-emission polarization ratio of 1.7 can be obtained under the condition of 15 nm in groove depth.