The optoelectronic properties of microcrystalline silicon solar cells with i-layers fabricated by hot-wire chemical vapour deposition (HWCVD) and plasma-enhanced chemical vapor depostion (PECVD) are compared. The current-voltage curves under illumination and in the dark, the quantum efficiency and the reflection in combination with the amorphous volume fraction as determined by Raman spectroscopy, are investigated to determine the difference, mainly in the open-circuit voltage, between these two technologies. Additionally, the voltage dependent quantum efficiency of μc-Si:H diodes is reassessed.