The scanning electron microscope (SEM) is a versatile instrument designed to provide high‑resolution imaging of surfaces at the micro‑ and nanoscale. Its core function is to reveal morphological, structural, and compositional details of materials with far greater depth of field and magnification than conventional optical microscopy. 

Its fundamental principle relies on a finely focused electron beam that is scanned across the specimen surface. As the electrons interact with the material, they generate a variety of signals—such as secondary electrons, backscattered electrons, and characteristic x‑rays—that are collected by dedicated detectors. By processing these signals, the SEM reconstructs detailed images and compositional maps with nanometer‑scale resolution. This strong electron–matter interaction provides both topographical contrast and elemental sensitivity, making the technique uniquely powerful for surface and microstructural analysis. 

SEM is important for materials research is that it provides direct access to the structural and compositional information of materials at the micro‑ and nanoscale. It allows researchers to investigate the morphology, organization, and quality of micro‑ and nanostructures, offering insights into growth processes, defect formation, and overall material performance. In the context of semiconductors and metallic systems, SEM plays a central role in bridging structural characterization with functional understanding, making it an indispensable tool for advancing applications in electronics, photonics, and nanotechnology.