Temperature dependence of silicon Raman lines

Abstract

The one‐phonon and two‐phonon Raman spectra have been measured in the temperature range 20–900 °C. The rate of decrease of the normalized frequencies with increase of temperature for the zone center, TO at L and TA at X, is 5.4×10⁻⁵/°C, while for TO at X and TA at L is lower, being 3.6×10⁻⁵/°C. We have also found that the relative intensity of Stokes and anti‐Stokes components of the Γ‐point optical phonon deviates significantly from the value involving only the phonon occupation number, particularly at high temperatures. The decrease of the Γ_25′ phonon from 521 cm⁻¹ at 20 °C to 493 cm⁻¹ at 900 °C should provide an unambiguous determination of the surface temperature due to laser heating.