Optical conductivity studies in heavily boron-doped diamond

The optical transmittance and reflectance of heavily boron-doped (2 x 10(20 ) cm(-3) < [B] < 2 x 10(21) cm(-3)) epitaxial diamond lavers deposited by M PCVD were measured in the infrared range. While T-dependent measurements co nfirmed the metallic character of such films, the overall spectral features were well reproduced by introducing Drude components in the fitting expres sion for the optical conductivity. The associated microscopic transport par ameters were quantitatively compared to those resulting from preliminary tr ansport measurements performed on the same samples. We show that room-tempe rature FTIR reflectance measurements provide an easy contactless characteri zation of the transport properties of such p(-) films, and we discuss what new information on carrier-phonon interaction as well as on the transport m echanism in the impurity band might be gained from temperature-dependent sp ectroscopic data.