Evolutionary computation for parameter extraction of organic thin film transistors using newly synthesized liquid crystalline nickel phthalocyanine

In this work, the topic of the detrimental contact effects in organic thin film transistors 1 (OTFTs) is revisited. In this case, contact effects are considered as a tool to enhance the characterization 2 procedures of OTFTs, achieving more accurate values for the fundamental parameters of the 3 transistor –threshold voltage, carrier mobility and on-off current ratio. The contact region is 4 also seen as a fundamental part of the device which is sensitive to physical, chemical and 5 fabrication variables. A compact model for OTFTs, which includes the effects of the contacts, 6 and a recent proposal of an associated evolutionary parameter extraction procedure, are reviewed. 7 Both the model and the procedure are used to assess the effect of the annealing temperature on 8 a nickel-1,4,8,11,15,18,22,25-octakis(hexyl)phthalocyanine (NiPc6) based OTFT. A review of the 9 importance of phthalocyanines in organic electronics is also provided. The characterization of the 10 contact region in NiPc6 OTFTs complements the results extracted from other physical-chemical 11 techniques such as differential scanning calorimetry or atomic force microscopy, in which the 12 transition from crystal to columnar mesophase imposes a limit for the optimum performance of the 13 annealed OTFTs.