Because the wavelength of electrons is much smaller than that of light, the optimal resolution attainable for TEM images is many orders of magnitude better than that from a light microscope. The TEM operates on the same basic principles as the light microscope but uses electrons instead of light. High resolution can be used to analyze the quality, shape, size and density of quantum wells, wires and dots. TEM can be used to study the growth of layers, their composition and defects in semiconductors. A high energy beam of electrons is shone through a very thin sample, and the interactions between the electrons and the atoms can be used to observe features such as the crystal structure and features in the structure like dislocations and grain boundaries. The transmission electron microscope is a very powerful tool for material science.
