Novel porphyrin-phthalocyanine heterodimers and heteropentamers: synthesis, characterization and application in organic solar cells

Two novel types of covalently ether-linked porphyrin-phthalocyanine (Por-Pc), heterodimer and heteropentamer, connected through the meso phenyl group of the porphyrin have been synthesized for the first time. The Por-Pc heterodimer and heteropentamer have more delocalized pi-electrons and therefore their conjugated degree is higher. In addition, these compounds possess better solubility and a wider light absorption than typical single porphyrins and phthalocyanines. Solar cell devices based on assynthesized porphyrin-phthalocyanine heterodimers and heteropentamers as donor materials and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) as the acceptor material are prepared and show a noticeably better performance. The suitable ZnPor-(O-ZnPc)(4) : PCBM weight ratio for photovoltaic devices is 4 : 1 and the highest photovoltaic properties are achieved based on ZnPor-(O-ZnPc)(4) : PCBM (4 : 1) annealed at 140 degrees C in a vacuum for 20 min. The highest PCE is 2.08.