Emissivity of silicon containing antimony at melting point and its thermal radiation model

Abstract

The effect of antimony on the emissivity of silicon has been investigated. The normal spectral emissivities were measured on silicon samples containing about 900 ppm Sb and no antimony at the melting point over a wavelength range between 500 and 1050 nm, and the experimental results were also examined theoretically. Experimental values of the emissivity at 633 nm for silicon containing no antimony were 0.49 for the solid and 0.27 for the liquid, for example. Emissivity values measured on silicon containing about 900 ppm Sb were in agreement with those measured on silicon containing no antimony within experimental error for both the solid and the liquid state. To calculate the emissivity of silicon on the basis of thermal radiation mechanisms, the free-electron model with damping and the restrained-electron model were applied to liquid and solid silicon, respectively. These models were found to describe well the emissivities of solid and liquid silicon. Emissivity values calculated for silicon containing about 900 ppm Sb were also in good agreement with those calculated for silicon containing no antimony, for both the solid and the liquid state. Theoretically, as well as experimentally, it has been confirmed that the presence of about 900 ppm Sb does not affect the emissitivities of solid and liquid silicon.