1. (a) If a semiconductor Ge sample is doped with 8 10'2 cm-3 As atoms. Assume that all impurities are fully ionized, explain why the Ge shows different type (n or p) at 250 K and 300K

(b) Write down the equation for the charge neutrality condition due to this As doping at 250 K in part (a).

1. (a) If a semiconductor Ge sample is doped with 8 x 10" cm As atoms. Assume that all impurities are fully ionized, explain why the Ge shows different type (n or p) at 250 K and 300 K. (6 marks) (b) Write down the equation for the charge neutrality condition due to this As doping at 250 K in part (a). (4 marks)