In photovoltaic devices, rather thin intrinsic layers of good quality materials are required and high deposition rates are a key point for a costeffective mass production. In a previous study we have shown that good quality amorphous silicon (a-Si:H) films can be deposited by matrix distributed electron cyclotron resonance (NIDECR) plasma CVD at very high deposition rates (similar to 2.5 nm/s). However, only thick films (> 1 mu in) exhibited good transport properties. A very poor thermal coupling between the substrate holder and the substrate is the main reason for such a behaviour. We present here experimental data which support this conclusion as well as the improved transport and defect-related properties of new very thin a-Si:H samples (thickness around 0.3 mu m) deposited at a higher temperature than the previous ones. (c) 2006 Elsevier B.V All rights reserved.