The inverse Meyer-Neldel rule in thin-film transistors with intrinsic heterogeneous silicon

The electron transport in undoped heterogeneous silicon deposited by hot-wire chemical vapor deposition is found to exhibit conventional as well as greatly pronounced inverse Meyer-Neldel behavior, when including this type of silicon in a field-effect device. The heterogeneous nature of the semiconductor in the channel region near to the gate insulator allows the Fermi level to be pushed deeply into the conduction-band tail states of the amorphous constituent of the material, which is the transport-limiting phase. By considering the band alignment at the interface of the crystalline inclusions and the amorphous phase, the occurrence of an activation energy smaller than 0.1 eV (required to observe the inverse Meyer-Neldel behavior) can be expected. (C) 1999 American Institute of Physics. [S0003-6951(99)03607-4].