Columnar arrangements of immiscible blend systems between octahexyl-substituted discotic liquid crystalline phthalocyanine and tetrabenzoporphyrin for organic solar cells

Abstract

Non-peripherally octahexyl substituted phthalocyanine (np-C6PcH2) and tetrabenzoporphyrin (np-C6TBPH2) were synthesized and characterized to study on the phase behavior and charge carrier mobility in the binary blend systems for ternary blend organic solar cells (OSCs). An ambiguous situation between pseudo hexagonal columnar mesophase (p-Colh) and rectangular columnar phase (Colr) was seen in the mixture of 1:1 blend from phase diagram and polarized optical microscopic images. The OSC device based on np-C6PcH2, np-C6TBPH2, and PC61BM (1:1:1 blend) showed higher performance than np-C6PcH2 and PC61BM-based solar cell by improved fill factor associated with semiconducting characteristic value.