Temperature Dependence of Interband Optical Absorption of Silicon at 1152,1064, 750, and 694 nm

The optical absorption coefficients of Si are calculated for 1152, 1064, 750, and 694 nm at elevated temperatures. The optical absorption processes employed in the calculation model are the indirect transitions of the valence band electrons to the set of lowest conduction band minima and involving the absorption or emission of acoustical and optical phonons. The calculated results are found to be in excellent agreement with the available experimental data up to a temperature of about 1000 K. Comparison is also made with the results calculated with the expressions employed earlier by Jellison and Modine. The present calculation model and the calculated results for Si should prove to be valuable references to many laser annealing heat flow calculations and solar cell analyses.