Problem-2: [2x4=8pts]A crucial tool for analysis and design of semiconductor devices is energy band diagram. Understand the use of such band energy diagram is very important. Answer following questions about

energy band-diagrams (i)What is a band diagram in relation to semiconductor materials? Draw a typical band-diagramfor a semiconductor material and mark the position of conduction-band, valence band and thebandgap. Why do crystal lattice (such as Si lattice) have bands of energy, while isolated Si-atoms do not have such bands?(ii) (iii)We know that electrons and holes that are responsible for conduction. But where are these located in this bands? (iv)Which direction energy of an electron increase along the y-axis of the band diagram? Energy of a hole?