Charge transport in disordered conducting polymers has been intensively researched for decades, but with many controversies unsolved. In this talk, I would like to introduce our recent works on two longlasting controversial issues, one is the non-Ohmic transport, the other is the Hall coefficient anomaly.

In the longstanding controversial topic about the origin of the non-Ohmic transport behaviors in conducting polymers, the non-Ohmic current-voltage (I-V) characters were widely simplified into the tunnelings at elementary resistors in the network. While in our recent research, via a systematic dimensionality dependent charge transport investigation, we show that the longstanding non-Ohmic transport problems in conducting polymers can only be solved within an inhomogeneous percolation network. The dimensionality’s possible mediation on percolation threshold p_c enabled us draw a smooth connection between two typically observed nonlinear phenomena - dissipative tunneling-like and coulomb blockade-like transport which are controversial against each other for years, and final unified them via the collective transport among percolation paths limited by the inhomogeneous tunneling resistors network, possible microscopic origins of the homogeneity are discussed within the Coulomb blockade.

 

Hall coefficient anomaly related to deviations in Hall carrier concentrations have always been recognized as signs of charge incoherence in organic semiconductors which lack ordered lattices. While we show that the Hall carrier concentration anomaly in doped polymers might be a result of semimetallization. Based on the observation of semimetallic states, a dual-channel model, in which electron and hole transport compensate the Hall voltages of each other, is employed to account for the anomaly. Observation of possible nonlinear Hall effect further supports the origin of Hall anomaly from semimetal states.