We report the influence of the field effect on the dc resistance and Hall coefficient in the strain-induced Mott insulating state of an organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br. Conductivity obeys the formula for an activated transport σ□=σ0exp(-W/kBT), where σ0 is a constant and W depends on the gate voltage. The gate-voltage dependence of the Hall coefficient shows that, unlike in conventional field-effect transistors, the effective mobility of dense hole carriers (∼1.6×1014cm-2) is enhanced by a positive gate voltage. This implies that carrier doping involves delocalization of intrinsic carriers that were initially localized due to electron correlation.
ASJC Scopus subject areas
- Physics and Astronomy(all)