corresponds to an ideal intrinsic region in which there is no impurity doping concentration. A reverse-bias voltage is applied to the PIN junction so that the total depletion width extends from - 2 um to + 2 pm. (a) Using Poisson's equation, calculate the magnitude of the electric field at x = 0. (b) Sketch the electric field through the PIN junction. (c) Calculate the reverse-bias voltage that must be applied. (N - N ) (cm3 ) 5 x 1015 +1 +2 -2 -1 -5 x 1015 Figure P5.33 Figure for Problem 5.33. i region