Temperature dependence of the first order Raman scattering in thin films of mu c-Si : H

The temperature effect on microcrystalline silicon (mu c-Si:H) films produc ed by R.E magnetron sputtering has been studied by Raman spectroscopy. The thermal behaviour of mu c-Si :H films and crystalline silicon is compared a nd interpreted on the basis of anharmonic effects. The authors have studied the first order Raman spectra of our films for several Ar+ laser powers. T he results show a blue shift and a broadening of the Raman spectra with inc reasing the laser power. This effect is not due to structural changes since it is reproducible. The sample temperature has been calculated according t o the well-known relation between Stokes and anti-Stokes components. The pr esent results show that the temperature effect is stronger in Irc-Si:H than in crystalline silicon. This difference can be attributed to the size of t he microcrystals, which are embedded in a amorphous matrix surrounded by a third phase called grain boundary. (C) 1999 Elsevier Science S.A. All right s reserved.