Record-High Mobility in Polycrystalline Phthalocyanine Transistors via Iodine-Mediated Trap Passivation

Abstract We report a simple iodine solution treatment that sets a new performance benchmark for polycrystalline phthalocyanine-based organic thin-film transistors (OTFTs). Applied to iso(Si3O)2SiPc, the treatment triggers an increase in average hole mobility to a record high value of 4.08 cm2V−1s−1. Additionally, this enhancement occurs without any structural modification and exhibits exceptional air stability, retaining 70% of the initial mobility after 50 days, a significant improvement over previous reports. Finite-element simulations and morphological studies reveal that iodine primarily passivates donor-like traps near the highest-occupied molecular orbital edge, with efficacy correlated to film roughness. Furthermore, we demonstrate the practical utility of treated devices in digital logic inverters. This work establishes iso(Si3O)2SiPc as a highly accessible, high-performance semiconductor and presents a facile chemical treatment strategy to overcome its trap-limited transport in OTFTs.