Band Gap Modulated by Electronic Superlattice in Blue Phosphorene

Exploring stable two-dimensional materials

with appropriate band gaps and high carrier mobility is

highly desirable due to the potential applications in

optoelectronic devices. Here, the electronic structures of

phosphorene on a Au(111) substrate are investigated by

scanning tunneling spectroscopy, angle-resolved photoemission

spectroscopy (ARPES), and density functional

theory (DFT) calculations. The substrate-induced phosphorene

superstructure gives a superlattice potential,

leading to a strong band folding effect of the sp band of

Au(111) on the band structure. The band gap could be clearly identified in the ARPES results after examining the folded sp

band. The value of the energy gap (∼1.1 eV) and the high charge carrier mobility comparable to that of black phosphorus,

which is engineered by the tensile strain, are revealed by the combination of ARPES results and DFT calculations.

Furthermore, the phosphorene layer on the Au(111) surface displays high surface inertness, leading to the absence of

multilayer phosphorene. All these results suggest that the phosphorene on Au(111) could be a promising candidate, not

only for fundamental research but also for nanoelectronic and optoelectronic applications