List of top Physics Questions on band theory of solids asked in COMEDK UGET

An intrinsic semiconductor has equal concentrations of hole and electron which is equal to \(4 \times 10^{8}\,\text{m}^{-3}\). During its conversion to extrinsic semiconductor, concentration of hole increases to \(8 \times 10^{10}\,\text{m}^{-3}\). The new electron concentration is:

What is the maximum wavelength of EM radiation required to move an electron from the valence band to conduction band of a semiconductor? [Given: Energy gap \( E_g = 1.98 \times 10^{-19} \, J \); Planck's constant \( h = 6.6 \times 10^{-34} \, Js \)]

Diamond is considered as an insulator because