The net potential energy E_N between two adjacent ions is sometimes represented by the expression: E_N = -C/r + D times exp (-r/rho) in which r is the interionic separation and C, d, and rho are constants whose values depend on the specific material. Derive an expression for the bonding energy E_0 in terms of the equilibrium interionic separation r_0 and the constants D and rho. Derive another expression for E_0 in terms of r_0, C and rho.

Subject: physics

Semiconductor Physics /Microelectronics: Why is the voltage drop across a PN junction expressed as V = (1/e0)*x_p*N_a*q*(W/2)? Can you derive it?

1.0 Biased PN Junctions Consider two PN diodes, A and B as depicted below. Suppose the junction area for each diode is 1.0 x10-8 cm² (1 square-micron) P-doped N-doped N = 1016 1/ cm3 Ng = 1017 1/cm³ X, *po Vo в P-doped Na = 1018 1/cm3 N-doped Ng = 1017 1/cm3 Х ро Xno V. a) At VD =0 Volts, which diode has the wider total depletion region width (value (in microns) and what is it? b) At Vp =0 Volts, in which diode the magnitude of the maximum electric field in the depletion region is the largest and what is its value (in V/cm)? c) Under a reverse bias Vp <0, which diode will breakdown first (i.e. at a smaller magnitude of the negative bias).