The gadolinium biphthalocyanine (GdPc2) nano/microwires were fabricated by the electrophoretic deposition (EPD) method from a mixed solution of chloroform and trifluoroacetic acid containing the protonated GdPc2. The morphologies of the nano/microwires were manipulated by deposition time, concentration in the mixed solvents, and applied voltage, and were characterized by AFM and SEM. By increasing the deposition time, four morphologies from nanoparticles, nanowire, to microrods and leaf-like microcrystallites were grown. Scissor-like Y-junction microwire were formed by tuning the applied voltage during the deposition. The EPD mechanism was studied by spectroscopy measurement. The possible molecular stacking of GdPc2 in the nano/microwires was as well investigated via X-ray diffraction. The deposited films of GdPc, showed interesting photoresponse in the near infrared (NIR) region, indicating the possibility of fabricating NIR photodetectors. (c) 2005 Elsevier B.V. All rights reserved.