The structural properties were studied of poly-Si films prepared by aluminium induced crystallization (AIC) of amorphous Si films (a-Si:H) deposited on glass substrates covered with Al layer. Raman and XRD spectroscopy were used for characterization of their short and long range order, respectively. The UV-reflectance spectra of poly-Si films were measured as well, and their surface morphology was observed by optical microscopy. The dependence was revealed of the structural and optical properties of the poly-Si films obtained on the annealing gas atmosphere and the hydrogen pressure during the deposition of the a-Si:H precursor, together with the correlation between them. The poly-Si films were applied in p-poly-Si/n-ZnO heterostructures; the I-V characteristics of the latter are presented and discussed.