The density of states mass of holes in semiconducting diamond

The band constants deduced from the results of cyclotron resonance measurements at 4.2 and 1.2 °K carried out by Rauch have been used to calculate the hole concentrations at temperatures for which kT > Δ, the spin-orbit splitting (= 0.006 eV). The calculated hole concentrations may be expressed in terms of a density of states mass m*, and the value of m* found is between 3.6 and 4.8 electron mass units (e-.m.u.). From their experiments on the variation of Hall constant with temperature Wedepohl and Kemmey deduced a value of m* = 0.4 ± 0.2 e-.m.u. Reasons for this discrepancy are discussed and it is shown that the experimentally observed value of m* can be obtained from the band structure if it is assumed that the relaxation times for carriers in one of the bands are much greater than in the other two bands. The value of mass is discussed in relation to the spin statistics of the acceptor state.