Effect of P donors on thermal phonon scattering in Si

Experimental results are presented for the thermal conductivity of P-doped Si over the concentration range 2.5x1014 to 1.1x1018cm-3 in the temperature region 1.5-50K. In the low concentration range, phonon scattering by isolated P donors is very weak in contrast with tnat by Group-V donors in Ge and Li donor in Si. This is due to the large valley orbit splitting of the P donor ground state. For samples with donor concentrations higher than 4.7x1017cm-3, thermal resistance becomes larger than that predicted by a simple theory on the basis of phonon scattering by a single donor center. In this concentration range, thermal conductivity has the temperature dependence T to the n at low temperature (T<=10K)