SEMICONDUCTING DIAMOND

Electronic properties of acceptors and donors and the valence band structure of diamond are discussed. Acceptor absorption spectra are considered in detail. Luttinger parameters deduced from the spectra and masses of the valence band gamma-1 = 4.24, gamma-2 = 0.82, gamma-3 = 1.71; m(h) = 0.86 m(o), m1 = 0.14 m(o), m(so) = 0.24 m(o) are compared with known data. The specific problems of diamond doping are considered: the rigid lattice and small radius of the carbon atom prevent the introduction of dopant atoms except boron (acceptor) and nitrogen (donor). A method of effective doping is proposed for non-equilibrium conditions of laser annealing, as is done successfully in silicon and other semiconductors. In diamond this process can be done under high pressure in the range of diamond stability. The dependence of the band structure of diamond on pressure is anomalous and does not follow Paul's empirical law for the family of diamond semiconductors.