List of top Physics Questions on Semiconductors asked in IIT JAM PH

A semiconductor \( pn \) junction at thermal equilibrium has the space charge density \( \rho(x) \) profile as shown in the figure. The figure that best depicts the variation of the electric field \( E \) with \( x \) is ( \( W \) denotes the width of the depletion layer):

For a semiconductor material, the conventional flat band energy diagram is shown in the figure. The variables Y, X respectively are:

For a forward biased p-n junction diode, which one of the following energy-band diagrams is correct? (\( \epsilon_F \) is the Fermi energy)

An intrinsic semiconductor of band gap 1.25 eV has an electron concentration \(10^{10} \, \text{cm}^{-3}\) at 300 K. Assume that its band gap is independent of temperature and that the electron concentration depends only exponentially on the temperature. If the electron concentration at 200 K is \( Y \times 10^N \, \text{cm}^{-3} \) (1<Y<10; N = integer), then the value of N is: