Thermoelectric properties and mobility activation energy of amorphous As20Se80−xTlx filmsM. Dongol, M. M. El-Nahass, M. Abou-zied and A. El-DenglaweyEur. Phys. J. Appl. Phys., 37 3 (2007) 257-260DOI: https://doi.org/10.1051/epjap:2007043