Thin films of porphyrin-perylene molecular array fabricated by electrophoresis methodology

Abstract

Thin solid films of organic conjugated molecules are at the center of organic electronics. Low solubility and high sublimation temperature of porphyrin-perylene arrays make it impossible to fabricate uniform solid films with spin-coating and vacuum deposition methodology, though these arrays have important applications in the area of opto-electronics. Here we show that high quality thin films of a porphyrin-perylene array can be prepared by electro-chemical deposition, a facile and widely used film-forming technique. The electrophoretic species are protonated porphyrin-perylene molecules, which allow us to grow molecular array films on electrodes. By annealing in ammonia atmosphere or in vacuum at elevated temperature, the protons coordinated with molecular arrays on the deposited films can be eliminated and the porphyrin-perylene arrays recovered to their pristine state.