2020-12-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/651600High temperature silicon-base materials, such as SiGe, FeSi2, and Mg2Si, have many applications, especially in thermoelectric applications. Thermoelectric devices are solid state thermal pumps that do not require moving parts for the conversion of heat and electricity. They have been widely used in converting waste heat to electricity, as well as electronic cooling or heating. In this three-year proposal, we attempt to study the melt and solution growth of SiGe and FeSi2 crystals through in situ observation experiments. Besides the observation of the interface morphologies, the grain control will be explored for further improvement of their thermoelectric properties. In the first year, we will develop an in situ observation and growth system for Si0.8Ge0.2 crystals. The growth morphology and the development of the grain will be investigated. The seeded growth using nano silicon particles will also be considered. The success of this work could be used for the mass production of fine grain SiGe thermoelectric materials. In the 2nd year, the solution growth using the Ge zone will be focused. The uniformity and quality of the grown SiGe crystals could be controlled through in situ observation by adjusting the heating/melting power. The thermoelectric properties of the SiGe crystals with different compositions and doping will be investigated as well. In the 3rd year, FeSi2 crystals will be focused. The grain growth and the formation of the-FeSi2 phase will be controlled by the cooling rate. The enhancement of electrical conductivity by adding SiGe will also be considered for high-performance thermoelectric materials. This 3-year project will provide the basic understanding of the growth of SiGe and FeSi2 crystals. The grain control technology developed here will also play a crucial role for the future production of Si-based thermoelectric materials.Silicon, germanium, SiGe, FeSi2, thermoelectric, crystal growth, grains