Synthesis,spectral characterization of CuPcF16 and its application in organic thin film transistors using p-6p as inducing layer

An air-stable n-channel semiconductor material, CuPcF₁₆, was synthesized in a slightly modified procedure and characterized by infrared (IR), X-ray diffraction (XRD), UV–vis and fluorescence spectra. CuPcF₁₆ showed a monomer characteristic in THF and pyridine while exhibited an aggregation property in DMF. The CuPcF₁₆/p-6p (CuPcF₁₆ on p-6p) organic thin film transistors (OTFTs) using CuPcF₁₆ as an active layer and p-6p as an inducing layer was fabricated by the physical vapor deposition technique. Charge carrier field-effect mobility (μ), I_on/I_off and threshold voltage (V_T) of the CuPcF₁₆/p-6p OTFTs were 0.07 cm²/V s, 10⁵ and 5.28 V, respectively. The charge mobility of the OTFTs was two or even three times higher than that of the conventional single layer CuPcF₁₆-based OTFTs. The improved performance was attributed to the introduction of p-6p to form a highly oriented and continuous film of CuPcF₁₆ with the molecular π–π conjugated direction parallel to the substrate.