Light extraction enhancement of InGaN MQW by reducing total internal reflection through surface plasmon effect

Coupling of a InGaN/GaN multi-quantum well (MQW) and semitransparent metal layer is shown to result in dramatic enhancement of spontaneous emission rate by the surface plasmon effect in the optical spectral range. A five-pairs 18.5nm InGaN/GaN MQW is positioned 175nm, form various thickness (t=5 similar to 50nm) silver layer. And periodic patterns (p=0.25 similar to 0.8 mu m) are defined in the top semitransparent metal layer by e-beam lithography, which are grating structures can be incorporated into the metal film to excite surface plasmon between the interference of the metal film and semiconductor. We have experimentally measured photoluminescence intensity and peak position of spontaneous emission of the fabricated structures and compared with the unprocessed samples, whilst still ensuring that most of the emission takes place into the surface plasmon (SP) mode. And the implication of these results for extracting light by reducing total internal reflection (TIR) from light emission diode is discussed.