Spray-coated contacts from an organic charge transfer complex solution for organic field-effect transistors

We demonstrate the deposition of films of the conducting charge transfer complex TTF-TCNQ from solution by spray-coating. The benefit of spray-coating is the ability to process large volumes of solution, therefore allowing the utilisation of compounds with very low solubility. The sheet resistance in the TTF-TCNQ film is similar to that of the commonly used organic PEDOT:PSS electrodes, with the added benefit of room temperature deposition and no additional thermal treatments. Spray-coated TTF-TCNQ is used as source and drain electrodes for transistors based on the organic semiconductor C8-BTBT, achieving similar performances in terms of mobility and turn-on voltage than when conventional contacts of MoOx/Au are used, whilst exhibiting a slight improvement in the linearity of the output characteristics.This work was mainly funded by the ERCStG 2012-306826 e-GAMES project. The authors also thank the Networking Research Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), the DGICT (Spain) with projects FANCY CTQ2016-80030-R and MAT2016-77852-C2-1-R (AEI/FEDER, UE) , Generalitat de Catalunya 2014-SGR-17, and the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496). A.C., I.T. and A. P.-R. are enrolled in the Materials Science PhD program of Universitat Autònoma de Barcelona and acknowledge FPU fellowship from the Ministry.Peer reviewe