1. The problem statement, all variables and given/known data (a)If a silicon crystal is doped with 10^15 cm−3 phosphorus atoms, find out the electron concentrations and hole concentrations in the silicon at room temperature. Find out the Fermi level. (b)Repeat at temperature = 0K 2. Relevant equations n*p=ni^2 n=2(2pi(n*)kT)^(3/2)exp-[(Ec-Ef)/(kT)] where (n*) = electron effective mass 3. The attempt at a solution I have calculated the hole concentration p = 10^15 per cm^3 and the electron concentration n = 1.96*10^5 electrons per cm^3 but I am not sure where to begin for calculating the fermi level. I don't know what to plug in for Ec the conduction band edge energy. For part (b) I am also unable to find ni, the intrinsic carrier concentration of silicon at T = 0K. Any suggestions or insight would be appreciated, thanks in advance.