Giant enhancement of solid solubility in monolayer alloys by selective orbital coupling

Article

关键词: HEXAGONAL BORON-NITRIDE;    GRAPHENE;    HETEROSTRUCTURES;    GROWTH;   

DOI  :  10.1103/PhysRevB.101.054201

来源: SCIE

【 摘 要 】

Solid solubility (SS) is one of the most important features of alloys, which is difficult to be largely tuned in the entire alloy concentrations by external approaches, e.g., the case for monolayer BNC [(BN)(1-x)(C-2)(x)] alloys. Here a novel mechanism of selective orbital coupling between wrong-bond states and surface states mediated by the specific substrate has been proposed to stabilize the wrong bonds and in turn significantly enhance the SS of (BN)(1-x)(C-2)(x). Surprisingly, we demonstrate that five ordered alloys can spontaneously be formed when (BN)(1-x)(C-2)(x) is grown on hcp-phase Cr. These ordered alloys can exhibit largely tunable quasiparticle band gaps (1.45-3.91 eV) and exciton binding energies (0.5-1.6 eV) in their free-standing forms. Importantly, the disordered (BN)(1-x)(C-2)(x) can be achieved on Cr substrate with a hugely reduced miscibility temperature from 5600 to 1200 K. These disordered alloys exhibit continuously tunable band gaps from 0 to 6 eV in their free-standing forms. Our discovery could potentially resolve the long-standing SS problem of BNC alloys and significantly extend their optoelectronic applications from infrared to deep ultraviolet.

【 授权许可】

Free