Photoluminescence (PL) spectroscopy is used to investigate defects and localized band tail states within the band gap of hydrogenated microcrystalline silicon (μc-Si:H) prepared by plasma enhanced chemical vapor deposition (PECVD) and hot wire chemical vapor deposition (HWCVD). The effect of the substrate temperature ( T S), which influences mainly the defect density, and silane concentration (SC), as the key parameter to control the microstructure of the material were varied. In high quality μc-Si:H films ( T S = 185–200 °C) a PL band (‘μc’-Si-band) is observed at ∼ 0.9–1.05 eV which is attributed to radiative recombination via localized band tail states in the microcrystalline phase. In μc-Si:H films prepared at higher T S (> 300 °C), an additional PL band at ∼ 0.7 eV with a width of ∼ 0.17 eV is found for both PECVD and HWCVD material. This band maintains its position at ∼ 0.7 eV with increasing SC in contrast to the observed shift of the ‘μc’-Si-band to higher energies. Studies of the temperature dependences of the PL peak energy and intensity for the two bands show: (i) the PL band at 0.7 eV remains unaffected upon increasing temperature, while the ‘μc’-Si-band shifts to lower energies, (ii) a much weaker quenching for the 0.7 eV band compared to the ‘μc’-Si-band. It was also found that the PL band at 0.7 eV exhibits a slightly stronger temperature dependence of the PL intensity compared to ‘defect’ band at 0.9 eV in a-Si:H suggesting similar recombination transition via deeper trap states. Due to a similar PL properties of the emission band previously observed in Czochralski-grown silicon (Cz–Si), the 0.7 eV band in μc-Si:H is assigned tentatively to defect-related transitions in the crystalline phase.