High vertical carrier mobility in the nanofiber films of a phthalocyanine derivative and its application to vertical-type transistors

A self-assembled nanofiber film of octabutoxy- phthalocyanine (H2PCOC4) was prepared by a simple spin-coating method with a mixed solvent. This film indicated a high vertical hole mobility up to 0.12 cm(2) V-1 s(-1) when the nanofiber structure is formed from a mixed solvent of chloroform and o-dichlorobenzene. The high vertical mobility is attributed to the unique crystal structure of H2PCOC4 and molecular arrangement in the fiber film. Quantum chemical calculations reveal that the crystal structure of H2PCOC4 enables two-dimensional carrier transport that is advantageous for the vertical transport. The nanofiber films were applied to vertical-type organic transistors, resulting in higher output current compared to a non-structured film.