THERMOELECTRIC-POWER IN QUASI-2-DIMENSIONAL SYSTEMS WITH SCATTERING OF CURRENT CARRIERS BY PHONONS

The thermopower a in electron systems with a quasi-two-dimensional ene rgy spectrum is investigated in the relaxation-time tensor approximati on. The longitudinal and transverse components of the thermopower are calculated for scattering of the current carriers by different types o f phonons. It is shown that the anisotropy of the thermopower in such systems is substantial. The dependence of alpha on the ratio of the Fe rmi level epsilon(F) to the half-width epsilon(0) of the one-dimension al conduction band is considered. For scattering by acoustical and non polar optical phonons, the thermopower changes sign: alpha becomes pos itive for epsilon(F)<epsilon(0). Comparison of the theory with publish ed experimental data demonstrates good qualitative agreement. (C) 1997 American Institute of Physics.