Photo-Hall effect measurements in P, N and B-doped diamond at low temperatures

Resistivity and Hall effect measurements are applied to understand the electronic properties of homoepitaxially grown n- and p-type CVD diamond in the wide temperature range 10–900 K. To overcome the high dark resistivity at low temperature, carrier concentration is enhanced by photo-excitation. It is found that the lifetime of photo-excited carriers decreases significantly at low temperature whereas their mobility increases. It is suggested that the short lifetime and the continuous photo-excitation can lead to the non-equilibrium stationary distribution of the photo-excited carriers at low lattice temperature. The enhanced average kinetic energy of the photo-excited carriers can effectively reduce ionized impurity scattering hence increasing the carrier mobility.