Influence of the morphology of the copper(II) phthalocyanine thin film on the performance of organic field-effect transistors

Organic thin-film transistors (OTFTs) with high crystallization copper phthalocyanine (CuPc) active layers were fabricated. The performance of CuPc OTFTs was studied without and with treatment by Solvent Vapor Annealing on CuPc film. The values of the threshold voltage without and with solvent-vapor annealing are −17   V and −10.5   V respectively. The field-effect mobility values in saturation region of CuPc thin-film transistors without and with Solvent Vapor Annealing are 0.00027   cm 2 /V   s and 0.0025   cm 2 /V   s respectively. Meanwhile, the high crystallization of the CuPc film with a larger grain size and less grain boundaries can be observed by investigating the morphology of the CuPc active layer through scanning electron microscopy and X-ray diffraction. The experimental results showed the decreased of the resistance of the conducting channel, that led to a performance improvement of the OTFTs.