A thin film transistor comprises a layer of organic semiconductor that comprises an N,N'-1,4,5,8-naphthalenetetracarboxylic acid diimide having at least one cycloalkyl group having a fluorinated substituent at its 4-position that adopts an equatorial orientation in the trans configuration of the cycloalkyl group and an axial orientation in the cis configuration of the cycloalkyl group. Such transistors can be a field effect transistor having a dielectric layer, a gate electrode, a source electrode and a drain electrode. The gate electrode and the thin film of organic semiconductor material both contact the dielectric layer, and the source electrode and the drain electrode both contact the thin film of organic semiconductor material.