Thermal Conductivity of ZnO Single Nanowire

The thermal conductivity of a single ZnO nanowire with diameter of similar to 150 nm was measured using a four-point-probe 3 omega method over a temperature range of 140-300 K. The measured thermal conductivity of ZnO nanowire is strongly reduced compared to bulk ZnO crystal due to the enhanced phonon-boundary and impurity (isotope) scattering. The maximum of the thermal conductivity is shifted to a higher temperature than that of bulk counterpart. Temperature dependent measurements show that beyond the low-temperature maximum, the thermal conductivity decreases with temperature as T-1.5 indicating strong impurity (isotope) scattering at intermediate and high temperatures.