Thermopower of phases and states of Si under high pressure

摘要

In the present work the technique of the high-pressure thermoelectric (TE) investigation has been developed for the phase transition recording at Si and the values of thermopower (S) for the different high pressure and metastable phases of Si have been obtained using the automated high-pressure set-up. The TE properties of various phases and states of Si were established which may be potentially used in Si-based nano-devices [1, 2]. The technique was shown also to be sensitive to the pre-treatments applied to a sample including annealing, doping, and irradiation by high-energy particles. The band structure calculations of the several phases of Si were carried out using linear muffin-tin orbital method (LMTO). The experimental values of thermoelectric power of various phases of Si up to 25 GPa are compared with the theoretical estimations basing on the band structure calculations performed. The theoretical calculations have confirmed the principal role of the contribution of d-band both in the forming of the electron states in the vicinity of Fermi level, as well as in the positive sign and the value of a thermoelectric power.