Effect of Phonon Confinement on Lattice Thermal Conductivity of Lead Telluride Quantum Well Structure

摘要

The paper examines the effect of spatial confinement of acoustic phonons on average group velocity an consequently the lattice thermal conductivity of a free-standing PbTe quantum well structure and their temperature dependence The average group velocity at 100 ? decreases 30% to the bulk value and falls more rapidly on reducing the width of quantum well. Moreover, the lattice thermal conductivity of 100 ? wide PbTe quantum well with value of 0.60 W/mK shows considerabl decrease of 70% compared to it's bulk value. It is observed that the effect of reduction in well width is less pronounce a temperature increases. This appears mainly due to dominance of umklapp processes over the confinement effects.