Characterization of Heat Propagation along Single Tin Dioxide Nanobelt Using the Thermoreflectance Method

In this paper, we studied heat transfer properties of a single tin dioxide nanobelt using non-contact high resolution thermoreflectance imaging technique. Temperature difference across the nanobelt was created by attaching its both ends to a microfabricated thin film heater and sensor pair. High resolution thermal images of the nanobelt and thin film devices were obtained at variant pulsing current amplitudes and frequencies, which allowed us to study the inherent thermal conductance of the nanobelt. Thermoreflectance coefficient change was found to significantly affect the thermoreflectance measurement results. INTRODUCTION One-dimensional nanostructures such as nanowires and nanobelts have been studied extensively during the past few years. Compared to bulk materials, in low dimensional inorganic nanostructures, quantum effects and high surface to volume ratio become important. The modified density of electronic states and increased surface scattering, etc, can alter the bulk properties substantially. These significant differences promise one-dimensional nanostructures important applications in the emerging nano-electronic and nano-optical industry. Among all functional nanostructures, the ribbonor beltlike metal oxide, such as tin dioxide (SnO2), zinc oxide (ZnO2) and Indium oxide (In2O3) nanostructures are unique due to the reason that they are essentially single-crystalline semiconductors without the presence of a surface insulating layer of native oxides [1]. Thermal transport property is one of the key factors limiting the performance and reliability of all nano-electronic and nano-optoelectronic devices. Metal oxide nanobelts or nanoribbons provide interesting systems for studying heat propagation behavior in low dimension. However, measurement of thermal properties on such small objects is non-trivial. As of today, only a few thermal characterization techniques are able to achieve nanoscale spatial resolution and sub-degree temperature resolution at the same time [2]. Here, we utilized thermoreflectance imaging technique. It is a non-contact temperature measurement technique that eliminates the thermal leakage error accompanied by making thermal contact. We have obtained thermal profiles along a single tin dioxide (SnO2) nanobelt with various bias currents amplitudes and frequencies applied to the attached micro device.