Which of the following is incorrect? A. Fermi level is the energy possessed by an electron at zero kelvin. B. Fermi level for an extrinsic semiconductor lies towards the conduction band for n-type semiconductor C. Fermi level for an extrinsic semiconductor lies towards the valence band for p-type semiconductor D. Fermi level is the energy possessed by an electron at zero degree Celsius.

Step-by-step solution

The Fermi level is defined as the highest energy state occupied by electrons in a system at absolute zero temperature, which is 0 Kelvin. Statement A describes this definition correctly. In an n-type semiconductor, the addition of donor impurities introduces energy levels just below the conduction band, causing the Fermi level to shift upwards towards the conduction band. Statement B is correct. In a p-type semiconductor, the addition of acceptor impurities introduces energy levels just above the valence band, caus