Continuous Liquid Metal Printed 2D Transparent Conductive Oxide Superlattices

Abstract 2D conducting metal oxides offer unprecedented control of thin film electrostatics at the nanoscale. A scalable, rapid, and low‐cost approach is presented to printing transparent conductive oxides (TCOs) via spontaneous low‐temperature Cabrera‐Mott oxidation of compliant liquid metals. Repeating heterostructures of these 2D oxide layers are exploited to produce an exceptional, 100× increase in conductivity while simultaneously raising the visible range optical transmittance. This innovative approach employs defect modulation doping at the type I heterojunction between InO x /GaO x , exceeding the achievable performance with ITO, which is otherwise limited by poor dopant activation at low temperatures. The exceptional performance of these multilayer 2D TCO superlattices exceeds that of competing TCOs printed from sol‐gels and nanoparticles, establishing a 100× faster process to fabricate flexible inorganic electronics.