Optical Characterization of InGaN Quantum Structures at the Nanoscale

This review paper presents an overview of the optical characterization techniques for Indium Gallium Nitride (InGaN) quantum well (QW) structures at a nanoscale. The two major techniques are reviewed-Electron Microscopy-Cathodoluminescence (EM-CL) and Scanning Near-field Optical Microscopy (SNOM). It elucidates the critical role these methodologies play in revealing the complex properties of InGaN QWs, including their structural characteristics, optical properties, carrier dynamics, and the effects of defects and doping. The review highlights key findings from a variety of studies, demonstrating how EM-CL and SNOM have contributed to the understanding of these micro-/nano- structures and their potential applications in high-efficiency optoelectronic devices. The widespread integration of InGaN-based optoelectronic devices across a spectrum of applications has precipitated intensive research across various fields including laser technology, photonic integrated circuits, and visible light communications. In the quest to characterize devices embedded with quantum structures at a nano-scale, this work reviews the two pivotal nano-optical characterization techniques: Scanning Near-field Optical Microscopy (SNOM) and Electron Microscopy-Cathodoluminescence (EM-CL).image