A carbon-doped tantalum dioxyfluoride as a superior electron transport material for high performance organic optoelectronics

The design and development of novel materials with superior charge transport capabilities plays an essential role for advancing the performance of electronic devices. Ternary and doped oxides can be potentially explored because of their tailored electronic energy levels, exceptional physical properties, high electrical conductivity, excellent robustness and enhanced chemical stability. Here, a route for improving metal oxide characteristics is proposed by preparing a novel ternary oxide, namely, carbon-doped tantalum dioxyfluoride (TaO ₂FC _x) through a straightforward synthetic route and exploring its effectiveness as an electron transport material in optoelectronic devices based on organic semiconductors. Among other devices, we fabricated fluorescent green organic light emitting diodes with current efficiencies of 16.53 cd/A and single-junction non-fullerene organic solar cells reaching power conversion efficiencies of 14.14% when using the novel oxide as electron transport material. Our devices also exhibited the additional advantage of high operational and temporal stability. Non-fullerene OSCs based on the novel compound showed unprecedented stability when exposed to UV light in air due to the non-defective nature of TaO ₂FC _x. We employed a tank of experiments combined with theoretical calculations to unravel the performance merits of this novel compound. This study reveals that properly engineered ternary oxides, in particular, TaO ₂FC _x or analogous materials can enable efficient electron transport in organic optoelectronics and are proposed as an attractive route for the broader field of optoelectronic devices including metal-organic perovskite, colloidal quantum dot and silicon optoelectronics.