Cathodoluminescence (CL) spectroscopy provides valuable insights into the optical and electronic properties of materials by analyzing photon emission induced by electron beam excitation. In this study, we present a novel CL detection system integrated into a transmission electron microscope (TEM) specimen stage, enabling high-resolution optical analysis of internal microstructures. The system features a parabolic mirror, a focusing lens, and a UV-VIS range optical fiber to maximize light collection and transmission efficiency, with performance further enhanced by a liquid nitrogen cooling setup. Using this system, we successfully performed CL mapping of InGaN/GaN multiple quantum wells (MQWs) and GaN thin films. The results revealed that threading dislocations act as non-radiative centers in GaN and locally increase the bandgap energy in InGaN MQWs, causing a blue-shift in CL emission. These findings support a model in which dislocations induce carrier delocalization, preserving high radiative efficiency despite high dislocation densities. This work demonstrates the effectiveness of the TEM-integrated CL system for nanoscale optical characterization, offering a new pathway for studying defect-related phenomena in semiconductor materials.

The utilization of scanning transmission electron microscopy (STEM) in conjunction with cathodoluminescence (CL) has emerged as a valuable tool for the investigation of material optical properties. In recent years, this technique has facilitated significant advancements in the fields of plasmonics and quantum emitters by surpassing prior technical restrictions. The review commences by providing an outline of the diverse STEM-CL operating modes and technical aspects of the instrumentation. The review explains the fundamental physics of light production under electron beam irradiation and the physical basis for interpreting STEM-CL experiments for different types of excitations. Additionally, the review compares STEM-CL to other related techniques such as scanning electron microscope CL, photoluminescence, and electron energy-loss spectroscopy.

For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk,Si3N4/Si, and Al/Si samples are used and observed the shapes milled from different sputtering rates,incident angles of Ga+ ions bombardment, beam current, and target material. These conditions also can beinfluenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions ofFIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damagedlayers caused by bombarding of Ga+ ions were observed on the surface of target materials. The simulatedresults were shown a little bit deviation with the experimental data due to relatively small sputtering rateon the sample surface. The simulation results showed about 10.6% tolerance from the measured data at200 pA. On the other hand, the improved analytical model of damaged layer was matched well withexperimental XTEM (cross-sectional transmission electron microscopy) data.