Electron energy-loss and soft X-ray emission study of boron nanobelts

The Growth Methods and Field Emission Studies of Low-Dimensional Boron-Based Nanostructures

Based on the morphology characteristics, low-dimensional (LD) nanostructures with high aspect ratio can be usually divided into nanowire, nanocone, nanotube, nanorod, nanoribbon, nanobelt and so on. Among numerous LD nanostructures, boron-based nanostructures attracted much interest in recent years because they have high melting-point, large electric and thermal conductivity, and low work function. Compared to traditional thermal emission, field emission (FE) has notable advantages, such as lower power dissipation, longer working life, room-temperature operation, higher brightness and faster switching speed. Most studies reveal they have lower turn-on and threshold fields as well as high current density, which are believed as ideal cold cathode nanomaterials. In this review, we will firstly introduce the growth methods of LD boron-based nanostructures (boron monoelement and rare-earth metal hexaboride). Then, we will discuss their FE properties and applications. At last, the conclusions and outlook will be summarized based on the above studies.

Unexpected reconstruction of the α-boron (111) surface

We report a novel reconstruction of the α-boron (111) surface, discovered using ab initio evolutionary structure prediction, and show that this unexpected neat structure has a much lower energy than the recently proposed (111)-I(R,(a)) surface. In this reconstruction, all single interstitial boron atoms bridge neighboring B(12) icosahedra by polar covalent bonds, and this satisfies the electron counting rule, leading to the reconstruction-induced metal-semiconductor transition. The peculiar charge transfer between the interstitial atoms and the icosahedra plays an important role in stabilizing the surface.