| Summary: | 碩士 === 國立交通大學 === 光電工程學系 === 99 === In this study, we presented high performance green emission semipolar {10-11} GaN-based nanopyramid light emitting diodes (LEDs) grown on c-plane sapphire substrate by selective area epitaxy (SAE).
The transmission electron microscopy (TEM) images suggest that the SAE can suppress the threading dislocation density in the semipolar {10-11} multiple quantum well (MQWs). Besides, from power dependent PL measurement, the internal electric field (IEF) of semipolar MQWs was reduced, and the internal quantum efficiency (IQE) was improved. Moreover, time-resolved PL (TRPL) measurement shows the radiative recombination lifetime of semipolar MQWs was shorter than that of c-plane MQWs. These results could strongly confirm the reduction of quantum confined Stark effect (QCSE) by using semipolar MQWs.
Finally, the L-I-V curves of green, olivine and orange emission nanopyramid LEDs were investigated by electroluminescence (EL) measurement. And the EL peak shift and emission behavior could be referred to the spatial distribution of nanopyramid, which was investigated by by cathodoluminescence (CL) measurement.
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