Spatially resolved characterizations of InGaN single quantum well in a GaN microrod

Abstract

For the last decade. GaN grown on a heterogeneous substrate has high luminescence efficiency and high thermal and chemical stability, despite its high defect density, and is widely used in light-emitting devices (LEDs). However, when InGaN quantum wells are grown in the c-axis direction on GaN, a strong internal field is applied to the structure, which lowers luminescence efficiency. The core-shell InGaN/GaN quantum well grown on the nonpolar facet of rod structure and rod structure with 3-D structure has the following advantages. The defect density can be reduced, and it is possible to reduce the influence of the internal electric field and improve luminescence efficiency. Due to these advantages of the rod structure, research using this structure is actively underway. The most important thing for the application to LEDs is the improvement of the efficiency, and it is necessary to understand quantum wells as the active layer of the structure. In this study, optical and structural analysis with the high spatial resolution was performed in order to observe the change of InGaN quantum well property according to the position in the core-shell GaN/InGaN quantum well structure formed on GaN microrod. By these measurement methods, the analysis of the phenomenon that the quantum well properties change with the position is carried out. Through this study, it is expected that we can go a step further to realize high efficiency three-dimensional GaN-based LEDs.