Resumen: Bulk and nanoscale molybdenum trioxide (MoO3) has shown impressive technologically relevant properties, but deeper investigation into 2D MoO3 has been prevented by the lack of reliable vapor-based synthesis and doping techniques. Herein, the successful synthesis of high-quality, few-layer MoO3 down to bilayer thickness via physical vapor deposition is reported. The electronic structure of MoO3 can be strongly modified by introducing oxygen substoichiometry (MoO3- x), which introduces gap states and increases conductivity. A dose-controlled electron irradiation technique to introduce oxygen vacancies into the few-layer MoO3 structure is presented, thereby adding n-type doping. By combining in situ transport with core-loss and monochromated low-loss scanning transmission electron microscopy–electron energy-loss spectroscopy studies, a detailed structure–property relationship is developed between Mo-oxidation state and resistance. Transport properties are reported for MoO3- x down to three layers thick, the most 2D-like MoO3- x transport hitherto reported. Combining these results with density functional theory calculations, a radiolysis-based mechanism for the irradiation-induced oxygen vacancy introduction is developed, including insights into favorable configurations of oxygen defects. These systematic studies represent an important step forward in bringing few-layer MoO3 and MoO3- x into the 2D family, as well as highlight the promise of MoO3- x as a functional, tunable electronic material. Idioma: Inglés DOI: 10.1002/adfm.201605380 Año: 2017 Publicado en: Advanced Functional Materials 27, 17 (2017), 1605380 [10 pp] ISSN: 1616-301X Factor impacto JCR: 13.325 (2017) Categ. JCR: CHEMISTRY, PHYSICAL rank: 8 / 146 = 0.055 (2017) - Q1 - T1 Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 13 / 285 = 0.046 (2017) - Q1 - T1 Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 6 / 92 = 0.065 (2017) - Q1 - T1 Categ. JCR: PHYSICS, CONDENSED MATTER rank: 7 / 67 = 0.104 (2017) - Q1 - T1 Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 11 / 171 = 0.064 (2017) - Q1 - T1 Categ. JCR: PHYSICS, APPLIED rank: 6 / 146 = 0.041 (2017) - Q1 - T1 Factor impacto SCIMAGO: 5.617 - Biomaterials (Q1) - Condensed Matter Physics (Q1) - Nanoscience and Nanotechnology (Q1) - Electronic, Optical and Magnetic Materials (Q1) - Electrochemistry (Q1)