Hydrogenated amorphous silicon films were deposited on the unstrained and strained Si substrates by an electron cyclotron resonance plasma source. The photoluminescence spectra show that emission energies are different from each other. The redshift of photoluminescence induced by the biaxial tensile stress is increased with decreasing the temperature in the range of 0.11–0.17 eV. The stress effect also enhances the quantum efficiency significantly. The pseudomorphic growth of Si on a relaxedSi0.75Ge0.25(100) surface provides the strain energy of about 0.17 eV. These comparable results indicate that the shift of emission energy is attributed to the stress effect perturbing the polysilane structure. ©1997 American Institute of Physics.