Field-induced migration of gold in molecular semiconductors

Abstract

We report on the degradation of field-effect devices due to the migration of gold from injection contacts into the channel region. The experimental results are obtained by THz spectroscopy on devices with a migration distance of 50 nm. The dependence of the degradation on gate voltage, as well as the partial reversibility, indicates that degradation is caused by field-induced transport of gold ions. The transport is found to be thermally activated with an activation energy independent of the field strength, which suggests that lattice deformations of the molecular semiconductor support the migration of gold.