Effect of the Solubilizing Groups of Fullerene Derivatives on the Charge Transport and Air-Stability of n-Channel Organic Transistors

Abstract

Solution-processable fullerene derivatives including [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have been frequently used as electron transporting materials in organic solar cells and organic field-effect transistors (OFETs). In recent years, much effort has been directed toward the development of n-channel OFETs based on fullerene derivatives resulting in high electron mobility and air-stability. To date, however, the effects of the molecular orbital energy levels of fullerene derivatives on polarity and air-stability have been far less investigated. Herein we report the results of our systematic study for assessing the effect of the number of solubilizing groups attached to the fullerene backbone on the OFET performance. Our findings provide insight into the molecular design and processing strategies towards high-performance n-channel OFETs based on fullerene derivatives.