During a thermal annealing process, the isomeric transformation from meridional (mer) into facial (fac) tris(8-hydroxyquinoline)-aluminum (Alq(3)) based on the infrared absorption was observed to be nearly complete around 375 degrees C. Then, in a physical vapor transport process with post-annealed fac-Alq3 as source powder (at source temperature of 375 degrees C), the effects from various substrate temperatures (T-sub from 285 to 346 degrees C) on the transformation from fac-Alq(3) into mer-Alq(3) isomers re-condensed on the substrate were studied again, and an isomeric transformation occurs at T-sub = 316 +/- 2 degrees C. For Tsub below 316 +/- 2 degrees C, the re-condensed mer-Alq(3) isomers tend to aggregate to form close-packed micron-rods, which are composed of alpha-phase crystallites with an average coherent length L similar to 46 nm. The photoluminescence (PL) spectra for these as-fabricated mer-Alq(3) films show typical green emission. However, for Tsub above 316 +/- 2 degrees C, the adsorbed fac-Alq(3) molecules on the substrate preserve their corresponding isomeric structure from the post-annealed fac-Alq(3) source and self-organize into flexible submicron-fibers. These samples are dominated by delta-phase crystallites with L similar to 57 nm. The PL spectra for these as-fabricated fac-Alq(3) films do emit blue luminescence. Besides, Raman scattering for these mer-Alq(3) and fac-Alq(3) molecules are also compared. (C) 2015 Elsevier B.V. All rights reserved.