The present paper reports the thermal equilibration in selenium-and sulphurdoped hydrogenated amorphous silicon thin films deposited by plasma-enhanced chemical vapour deposition. The conductivity of Se-and S-doped a-Si:H is observed to be very sensitive to the rate at which the samples are cooled following the high temperature anneal. Arrhenius plots of conductivity for various doped films revealed thermal equilibration above the equilibration temperature, T E , thus accounting for larger activation energies. The barrier energy is lower for a-Si,Se:H than for a-Si,S:H, due to a higher defect density in S-doped films.