1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I think before getting the steady state, after doping there are more electrons in n-region and there are more holes in p-region, so the more electrons go towards the p-region and more holes go toward the n - region. Consequently the charges on the two sides of the depletion layer gets increased because of the doping. After reaching the steady state, for an electron from n region going towards p-region, the negative charge at the starting of the p-region repels it and the positive charge at the n-region attracts the electron. The resultant force on the electron due to these two source of charges in both type of p-n junction( doped and pure) should remain same. Since, in case of doped p-n junction, the charges is comparatively more,the distance between the two sources of charges should get increased. Consequently, the width of the depletion layer should get increased. The correct option is (iii). Right?