Photoabsorption Spectra of Nano-Crystalline Silicon Films

The photoabsorption spectra of nano-crystalline silicon (nc-Si :H) films were measured by means of constant photoconductivity method. We investigated the changes of absorption spectra with the increasing of crystallinity as the deposited films are amorphous, microcrystalline and nano-crystalline. We found that in nc-Si : H the transition processes in the interfacial region between the grains predominate the whole range of the absorption spectra. We related the phenomenon to the structural changes in the material.