Electrical and Optical Properties of Type IIb Diamonds

The d.c. Hall coefficient and resistivity of six semiconducting diamonds have been measured as a function of temperature from 200 to 800°K. All the diamonds were p-type semiconductors. From the measurements the effective mass of the charge carriers, the concentration of donor and acceptor centres, the activation energy of the acceptors (close to 0.34 eV) and the temperature dependence of the Hall mobility have been calculated. At high temperatures the mobility varies as T-2.8.