Aligned beta-phase F8 thin films have been prepared by exposing aligned crystalline F8 thin films to toluene vapor. Aligned beta-phase F8 thin films with a high dichroic ratio and a high photo luminescence (PL) polarization ratio have been obtained by the optimization of the exposure time. Absorption and PL spectra of aligned beta-phase F8 thin films exhibit the temperature dependence similar to those of nonaligned beta-phase F8 thin films and the dichroic ratio and PL polarization ratio are independent of temperature. (C) 2008 Elsevier B.V. All rights reserved.