Non-Gaussian photoluminescence peaks observed in a-Si:H-based structures at 6K are interpreted as a consequence of the presence of different phases in material. Thin films of amorphous silicon deposited on glass substrate have been analyzed. The main aims of the contribution are (i) analysis of numerical data obtained by fitting procedure and (ii) formulation of corresponding conclusions in terms of structural properties of sample. Spectrum of a-Si: H-based samples can be interpreted as superposition of photoluminescence signals arising from two domains with different degrees of structural disordering. By our knowledge this result corresponds to real situation from view of structural properties of amorphous hydrogenated silicon. Under certain circumstances, decomposition of photoluminescence spectrum can give information of geometrical structure of sample. (C) 2010 Elsevier B. V. All rights reserved.