As a two-dimensional (2D) inorganic molecular van der Waals crystal, Sb2O3 has been widely recognized as an excellent dielectric and encapsulation material due to its wide bandgap, high dielectric constant (κ), and remarkably high air stability. Considering the significance and potential application of Sb2O3 in future electronic devices, it is valuable to summarize its recent advancements. In this review, we present the latest progress on 2D Sb2O3 flakes and films, encompassing synthesis methods, physical properties, and device applications. First, preparation strategies such as chemical vapor deposition, vertical physical vapor deposition, thermal evaporation deposition, liquid metal synthesis, and atomic layer deposition growth routes are highlighted. Subsequently, the mechanical properties and the phase transition mechanisms of 2D Sb2O3 are presented. Moreover, device applications, including encapsulation layer, photodetector, and gate dielectric, are demonstrated. Finally, we outline the future challenges and research priorities of 2D Sb2O3 materials.

Selective oxidation of the silicon element of silicon germanium (SiGe) alloys during thermal oxidation is a very important and technologically relevant mechanism used to fabricate a variety of microelectronic devices. We develop here a simple integrative approach involving vapor–liquid–solid (VLS) growth followed by selective oxidation steps to the construction of core–shell nanowires and higher-level ordered systems with scalable configurations. We examine the selective oxidation/condensation process under nonequilibrium conditions that gives rise to spontaneous formation of core–shell structures by germanium condensation. We contrast this strategy that uses reaction-diffusion-segregation mechanisms to produce coherently strained structures with highly configurable geometry and abrupt interfaces with growth-based processes which lead to low strained systems with nonuniform composition, three-dimensional morphology, and broad core–shell interface. We specially focus on SiGe core–shell nanowires and demonstrate that they can have up to 70% Ge-rich shell and 2% homogeneous strain with core diameter as small as 14 nm. Key elements of the building process associated with this approach are identified with regard to existing theoretical models. Moreover, starting from results of ab initio calculations, we discuss the electronic structure of these novel nanostructures as well as their wide potential for advanced device applications.

Further transistor scaling requires gate dielectric materials with both high dielectric constant and wide bandgap to improve gate control and suppress leakage current. However, these two properties typically exhibit an inverse relationship, making it challenging to simultaneously optimize both. Here, we report the exfoliation of KBe₂BO₃F₂ (KBBF) dielectric nanosheets that overcome this trade-off. The material possesses a wide band gap exceeding 8 eV and a bulk dielectric constant of 63. Such dielectric properties give rise to a low leakage current of 10⁻⁶ A cm⁻² at an equivalent oxide thickness of 0.62 nm and a high gate voltage of 15 V, and is predicted to work stably for 10 years at 6.6 V. 2D MoS₂ transistors gated by KBBF show a subthreshold swing of 60 mV dec⁻¹, reaching the theoretical limit at room temperature, and an on/off ratio up to 10⁹. Moreover, the good electrostatic controllability of KBBF enables the fabrication of short-channel devices and inverter circuits. Our research broadens the scope of dielectrics and provides promising opportunities for the development of low-power 2D electronics and integrated circuits.