Highly Rectifying Water-Mediated Hydrogen Bond-Coupled Organic–Inorganic Interfaces

Asymmetrically conducting interfaces are the building blocks of electronic devices. While p–n junction diodes made of seminal inorganic semiconductors with rectification ratios close to the theoretical limits are routinely fabricated, the analogous organic–inorganic and organic–organic interfaces are still too leaky to afford functional use. We report fabricating highly rectifying organic–inorganic interfaces by forming water-mediated hydrogen bonds between the hydrophilic surfaces of a hole-conducting polymer anode and a polycrystalline n-type metal oxide cathode. These hydrogen bonds simultaneously strengthen the anode–cathode electronic coupling, facilitate the matching between their incompatible surface structures, and passivate the detrimental surface imperfections. Compared to an analogous directly joined interface, our hydrogen-bonded Au-PEDOT:PSS–H 2 O–TiO 2 -Ti diodes demonstrate 10 5 times higher rectification ratios. These results illustrate the strong electronic coupling power of the hydrogen bonds on a macroscopic scale and underscore the hydrogen-bonded interfaces as the building blocks of fabricating organic electronic and optoelectronic devices. The presented interface model is anticipated to advance designing electronic devices based on the organic–organic and organic–inorganic hetero-interfaces. Described electronic implications of hydrogen bonding on the conductive polymer interfaces are anticipated to be impactful in the organic electronics and neuromorphic engineering.