Recent developments in depositing high quality intrinsic and doped microcrystalline Si at low temperatures, 100-140degreesC, and high rates of similar to6 nm/s are reviewed. A new high-pressure depletion deposition method is described that suppresses ion bombardment and yields low defect densities. Passivation of oxygen related donors by hydrogen is discussed as well as the dissociation of passivated B-H dopant atoms by annealing at 200degreesC. Interface damage effects on superstrate and substrate cells are identified. The influence of the microcrystalline texture formed spontaneously during growth on optimizing optical confinement has been studied. (C) 2002 Published by Elsevier Science B.V.