Transmission electron microscopy is a microscopic technique in which an electron beam is transmitted through a thin specimen. Interaction of energetic electrons with the specimen in the vacuum chamber produces a high-resolution, black and white image on an imaging device, such as a fluorescent screen, on a layer of photographic film, or to be detected by a sensor such as a CCD camera. The TEM has the added advantage of greater resolution - in hi-res even as small as a single column of atoms, owing to the small de Broglie wavelength of electrons.` Alternate modes of TEM (STEM, HAADF, EDS) allow to observe modulations in chemical identity, crystal orientation, electronic structure and sample induced electron phase shift as well as the regular absorption based imaging.