Lattice Thermal Conductivity of Wurtzite Bulk and Zinc Blende CdSe Nanowires and Nanoplayer

Abstract

By using Morelli-Callaway model and some structure dependent parameters, theoretical calculations of LTC for wurtzite Bulk CdSe, zinc blende CdSe nanowire and nanolayer are performed. The theoretical and experimental correlation for CdSe NWs with diameter 41, 52 and 88nm and nanolayer with thickness of 4.3nm are investigated. While, the direction of growth of ZB CdSe is one equation for longitudinal and two different equation for transverse mode are used for calculating acoustic group velocity. Therefore, Morelli-Callaway model splits to three branches. There are six phonon transfer scattering rate, which are umklapp, normal, boundary impurity, dislocation, and phonon-electron scattering rate. In different temperatures, different phonon scattering process appeal. The shape of LTC as a function of temperature has a bell shape that all phonon scattering rate configured this shape. The peak of lattice thermal conductivity shift to higher temperature with decreasing the size of CdSe nanostructure. In summarize, the LTC for a particular temperature depends on the size and crystal structure. At 300K thermal conductivity of WZ bulk CdSe has less value than all ZB CdSe NWs mentioned in this work. Also quantum confinement effect cause mechanical and thermal parameters change with decreasing the size and dimension of CdSe semiconductor.