The electrical conductivity of a-Si,Se:H and a-Si,S:H films prepared by plasma enhanced chemical vapour deposition on Corning 7059 glass. The conductivity measured in the temperature range of 300-470 K was analyzed to exhibit two different transport mechanisms. In the high temperature range (370-470 K), the conduction was found to be of activated type while at low temperature (less than 370 K), it was observed to follow variable range hopping. The experimental results have also been analyzed using Meyer-Neldel Rule. A consequence of the Meyer-Neldel rule is the occurrence of the characteristic energy E-MN( = kT(MN)) for Se and S-doped a-Si:H films 54 meV and 50 meV, respectively. This corresponds to characteristic temperature of 616 and 591 K where the conductivity data becomes independent of dopant concentrations. (c) 2007 Elsevier Ltd. All rights reserved.