Fluorinated Hydrogenated Amorphous Silicon Alloys. Vibrational Excitations of Chains

The vibrational excitations of the various fluorine hydrogen complexes, and the polysilane‐like conformations in amorphous silicon are studied after employing a valence force field mode1 (VFFM) in a cluster Bethe lattice formulation. The calculated high frequencies are seen to be in excellent agreement with the infrared and Raman data. Some calculated peaks appearing at 214 and near 600 cm −1 have not been detected so far. More experimental measurements on a‐Si : F : H alloys need to be performed especially in the low‐frequency region ≈600 cm −1 to detect the predicted structure.