Analysis of the infrared transmission data of amorphous silicon and amorphous silicon alloy films

Abstract

The conversion of infrared transmission spectra to absorption spectra of amorphous silicon and amorphous silicon alloys has been considered. The use of an appropriate form of the equation for coherent transmission allows one to separate the terms, accounting for interference in the non-absorbing and absorbing regions. The source of error arising in the treatment of coherent transmission by the equation for incoherent transmission is clearly identified. A fast convergent iterative method for the conversion of transmission to absorption spectra has been proposed-it does not require limits on the values of the optical constants. However, the method uses definite approximations which have been estimated. Computer simulations have shown that the error is about 10% for the most unfavourable case.