Supersonic molecular beams deposition of alpha-quaterthiophene: Enhanced growth control and devices performances

The alpha-quatertiophene is widely considered an interesting material for the realization of organic electronics and opto-electronics. Compared to other oligothiophenes, the performances of transistors based on this compound are limited by its kind of growth on the typical materials used for device realization. Here we show that via seeded supersonic beams we can lead to a nice improvement of both morphological and electrical properties of the film grown, through a better control of the initial state of the precursor in the vapor phase. Using the high kinetic energy achievable in the supersonic beams, we increase the dimensions of the grains and the coalescence of different islands, limiting the grain boundary formation. As consequence, the performance of the realized field effect transistors is enhanced of one order of magnitude.