Analysis of rectifying behavior of novel ball-type binuclear phthalocyanine based devices

Abstract

A new mono substituted derivatives 1 and 2 were prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with pyridine-2,6-dimethylol. Novel metallophthalocyanines 3-4 (M = Zn, Co respectively), and ball-type binuclear phthalocyanines 5-6 with four peripheral pyridine-2,6-dimethyloxy groups were synthesized by cyclotetramerization of the phthalonitrile and characterized by elemental analyses, FT-IR, H-1 NMR, UV-Vis and MALDI-TOF MS spectral data. The effects of molecular structure on the charge transport properties of novel metallophthalocyanines 3-4 and ball-type binuclear phthalocyanines 5-6 with four peripheral pyridine-2,6-dimethyloxy groups based devices are investigated using I-V measurements. From our study, we found that ball type films showed an enhanced mobility of nearly ten times that of typical mono Pcs. At low voltages (V < 1V) all the films showed an ohmic conduction, whereas at higher voltage (V > 1V) levels the conduction is dominated by space charged limited conduction (SCLC) with exponential distribution of trapping levels. (C) 2013 Elsevier B.V. All rights reserved.