Using atomic steps to induce texture in polycrystalline pentacene films

Abstract

The authors have studied the effect of substrate atomic steps on the azimuthal alignment of crystals in polycrystalline pentacene films. The substrates used were Si (111) with a low miscut angle and these were annealed at high temperature in ultrahigh vacuum before the pentacene deposition to produce surfaces with atomically flat terraces and arrays of parallel atomic steps. By depositing pentacene on these heated samples, at a low deposition rate, the authors have succeeded in obtaining significant azimuthal alignment of the pentacene crystals relative to the atomic steps.