Consider cryogenically cooled Si semiconductor doped with an unknown dopant type and dopant concentration Ndop. Based on the below measured carrier concentration (n or p) and Hall coefficient Ry values as functions of temperature, find out the doping type (n- or p- doping), the doping concentration Ndop; and the ionization energy (Ed or E.). Finally, based on the ionization energy, make an educated guess of what element the dopant could have been. 10-2 10 25 103 10 25 104 10 24 Carrier concentration [1/m *] Hall coefficient R [1/(C - m)] 105 1023 106 1022 -7 30 35 40 45 50 55 60 65 70 75 8010 21 Temperature T (K) Figure 1: Carrier concentrations and Hall coefficients of mystery-doped Si as functions of temperature