Unit 1
Introduction
Introduction to nanotechnology, comparison of bulk and nanomaterials – change in band gap and large surface to volume ratio, classification of nanostructured materials. Synthesis of nanomaterials – classification of fabrication methods – top down and bottom up methods.
Concept of quantum confinement and phonon confinement
Basic concepts – excitons, effective mass, free electron theory and its features, band structure of solids. Bulk to nano transition – density of states, potential well – quantum confinement effect – weak and strong confinement regime. Electron confinement in infinitely deep square well, confinement in two and three dimension. Blue shift of band gap – effective mass approximation. Vibrational properties of solids – phonon confinement effect and presence of surface modes.