Abstract

The dielectric properties and electromagnetic wave absorbing performance of granular polysilicon have important influences on microwave smelting efficiency. In this study, the dielectric parameters (dielectric constant, dielectric loss factor and loss tangent) of granular polysilicon were measured from room temperature (25 °C) to 800 °C at 2450 MHz by using the cylindrical cavity perturbation method, and the reflection loss of granular polysilicon was calculated according to the theory of electromagnetic wave transmission line, and then the effects of temperature on microwave absorbing performance was analyzed. The results indicated that the dielectric constant and dielectric factor loss of granular polysilicon change little before 300 °C, but when the temperature is higher than 300 °C, the dielectric constant and dielectric loss factor increase gradually. The microwave absorbing performance of granular polysilicon fluctuates with the increase of granules thickness, there are multiple absorption peaks, and the position and intensity of absorption peaks change with the increasing temperature. This study provides theoretical guidance for the optimization of smelting process parameters of granular polysilicon and the design of microwave smelting equipment.

摘要

粒状多晶硅的介电性能和电磁波吸收性能对微波熔炼效率有重要影响。在这项研究中，使用圆筒形腔扰动法在室温（25°C）至800°C和2450 MHz下测量了颗粒状多晶硅的介电参数（介电常数，介电损耗因子和损耗角正切），以及反射损耗根据电磁波传输线理论计算了颗粒状多晶硅的含量，然后分析了温度对微波吸收性能的影响。结果表明，粒状多晶硅的介电常数和介电因子损失在300°C之前变化不大，但是当温度高于300°C时，介电常数和介电损耗因子逐渐增加。粒状多晶硅的微波吸收性能随颗粒厚度的增加而波动，存在多个吸收峰，且吸收峰的位置和强度随温度的升高而变化。本研究为粒状多晶硅熔炼工艺参数的优化和微波熔炼设备的设计提供了理论指导。