Solution-Processable n-Type Tin Phthalocyanines in Organic Thin Film Transistors and as Ternary Additives in Organic Photovoltaics

Tin phthalocyanines have shown promise in both organic thin film transistors (OTFTs) and organic photovoltaics (OPVs); however, no examples of solution processable axial derivatives have been reported. We synthesized and characterized tin phthalocyanines (SnPcs) with tributylsilane and trihexylsilane axial functional groups and examined their performance in OTFTs and in poly(3-hexylthiophene):phenyl-C-61-butyric acid methyl ester (P3HT:PC61BM) OPV devices as ternary additives. We also report the OTFT performance of the previously studied trialkylsilane silicon phthalocyanines for comparison. In polycrystalline OTFTs the tin derivatives show higher electron mobilities than their silicon counterparts due to increased molecular interactions. As a ternary additive in OPV devices, similar to the SiPc analogues, both SnPc derivatives show an EQE contribution >20% in the range 650-750 nm. These results suggest soluble SnPcs show potential as active materials in OTFTs and OPVs, justifying further investigation into additional derivatives of SnPcs.