A TIPS-TPDO-tetraCN-Based n-Type Organic Field-Effect Transistor with a Cross-linked PMMA Polymer Gate Dielectric

Recent improvement in the performance of the n-type organic semiconductors as well as thin, gate dielectrics based on cross-linked polymers: offers new opportunities to develop high-performance low-voltage n-type OFETs suitable for organic complementary circuits. Using TIPS-tetracyano-triphenodioxazine (TIPS-TPDO-tetracN) and cross-linked poly(methyl methacrylate) (c-PMMA.),, respectively as n-type organic semiconductor and gate dielectric, linear regime field-effect mobility (1.8 +/- 0.2) X 10(-2) cm(2) V(-1)s(-1), small spatial standard deviation of threshold voltage (similar to 0.1 V), and operating voltage less than 3 V are attainable with the same device structure and contact materials used commonly for p-type OFETs. Through comparative static and dynamic characterizations of c-PMMA and PMMA gate dielectrics, it is shown that both smaller thickness and larger relative permittivity of c-PMMA. contributes to reduced operating voltage. Furthermore, negligible hysteresis brings evidence to small trap states in the semiconductor near gate dielectric of the n-type OFETs with c-PMMA. The use of TIPS-TPDO-tetraCN and c-PMMA is fully compatible with polyethylene terephthalate substrate, giving promise to various flexible applications.