On January 20, 2026, a groundbreaking research paper titled "Metallic Charge Transport in Conjugated Molecular Bilayers" was published in Nature Electronics by a collaborative team led by Academician Shi Yi and Professor Li Yun from the School of Electronic Science and Engineering at Nanjing University, in conjunction with Assistant Professor Wang Qijing from the School of Integrated Circuits. The international collaboration also included esteemed Professor Henning Sirringhaus from the University of Cambridge in the UK and Professor Qiao Jingsi from the Beijing Institute of Technology.

Metallic transport, a phenomenon where a material's conductivity rises as temperature falls—previously observed solely in inorganic semiconductors—was the focal point of this study. The research team introduced and substantiated a novel mechanism termed the "van der Waals-bridged molecular bilayer transport network." This was achieved by fortifying conjugated coupling between ultrathin single-crystal molecular layers, which in turn dramatically enhanced interlayer charge tunneling and orbital coupling. The approach effectively curbed dynamic disorder stemming from molecular vibrations and diminished Coulomb interactions among charge carriers.

For the first time, metallic transport was realized in undoped organic semiconductors across an ultra-wide temperature range extending down to 8 K. This achievement was marked by a conductivity of 245 S cm⁻¹ and a Hall mobility surpassing 100 cm² V⁻¹ s⁻¹. This leap forward surpassed the performance thresholds of organic field-effect transistors, attaining conductivity levels on par with those of heavily doped silicon and wide-bandgap GaAs inorganic materials.

This discovery challenges the long-held notion that "weak van der Waals interactions inevitably lead to carrier localization at low temperatures." It breaks through the performance bottlenecks of organic materials, offering fresh perspectives for the exploration of high-performance organic electronic materials.

Moreover, by deliberately introducing defects, the team observed, for the first time in organic semiconductors, disorder-induced metal-insulator phase transitions and quantum critical scaling behavior. This extends the realm of quantum phase transition physics from traditional inorganic semiconductors and strongly correlated electron systems to organic systems, providing an exemplary model for delving into organic Mott–Anderson systems.

This pioneering research was a collective effort involving multiple institutions, including Nanjing University, the University of Cambridge, Renmin University of China, and the Beijing Institute of Technology. It received support from prestigious projects such as the National Key Research and Development Program and the National Natural Science Foundation of China.