Amorphous silicon is generally considered unsuitable for light emitting applications because of the indirect nature of its bandgap. Many efforts have been devoted towards the research of different systems compatible with a-Si technology and able to act as light emitters; among these are low-dimensional amorphous silicon structures. In these structures, it has been shown that, zero- phonon optical transitions are allowed and oscillator strength of the zero- phonon transition is significantly enhanced . Therefore, it is expected, the light emission properties will be improved. The aim of this study is to develop a photoluminescence a-SiQDs model, where its radiative recombination occurs at room temperature. This model is suggested, for the first time, both the effect of concepts, spatial and quantum confinements. This study may be able to show the differences between them. In fact, these concepts will be used to see the possibility for shifting the luminescence spectrum of a-SiQDs into visible region. The tuning the visible light by controlling the size of QDs also is taken into account.