Experimental observation of electroluminescence enhancement on green LEDs mediated by surface plasmons

Abstract

We experimentally demonstrate the 1.5-fold enhancement of the electroluminescence (EL) of surface-plasmon (SP)-mediated green LEDs. On the p-clad surface of InGaN/GaN multi-quantum well LEDs, a 2-dimensional, second-order grating structure is textured and coated with an Ag electrode. With this setup, a larger EL enhancement factor is obtained at a higher injected current, which suggests that SP-LEDs can be a possible solution to efficiency droop, which is one of the main problems in developing high-power LEDs. Details regarding the implementation of our device are discussed.

Tunable Emission Enhancement in Surface Plasmon‐Enhanced GaN Light‐Emitting Diode Based on the Ag–SiO2 (Ag‐Rich) Cermet Material

“…These results demonstrated that the improve the light extraction efficiency and SPP of GaN-LED. [51][52][53][54] If the appropriate micro-/nanogratings are fabricated on the designed or optimized structure in this article, the emission efficiency will be further enhanced. In recent years, a large number of new technologies about LED have emerged.…”

Optimal design of green InGaN/GaN LEDs mediated by surface-plasmon gratings

“…First of all, there are several technical difficulties in realizing 10e20 nm thin p-GaN layer without any serious damage of the system. When one control the separation gap by etching methods, for example, the active layer could be easily damaged [19], and the overall improvement factor reported in a recent experiment is around 1.5-fold with the separation gap of 30 nm [20]. It must be challenging to technically get the separation gap below 20 nm and to estimate an attainable improvement in such situations by further controlling the radiation direction.…”

Experimental observation of a practical limit on enhancement of the spontaneous emission rate in blue GaN-LEDs by mediating surface plasmons

“…However, it is not straightforward to experimentally control the separation gap on demand. When the metal grating is patterned directly on the p-clad layer by dry etching methods, the damage in the p-clad and the active layers becomes more severe with a smaller separation gap [16]. In this study, we adapted a different approaching of forming a grating on an additional layer of the p-clad and over-coating it with Ag.…”