Evolution of Low-Dimensional Phosphorus Allotropes on Ag(111)

Elemental two-dimensional (2D) materials exhibiting intriguing properties have great potential applications in next-generation electronics. However, controlling single-phase synthesis might be challenging due to the existence of various allotropes with comparable stability. Here, low-dimensional phosphorus (P) is used as a prototype for the understanding of the competition among a series of 0D-2D allotropes upon adsorption. With a combination of theoretical calculations and scanning tunneling microscopy, we find that the formation of P allotropes significantly depends on the bond angle, coordination number, and atomic density. As a result, P atoms tend to form black phosphorene (BP)-like chains and pentamer molecules at low atomic density and 2D buckling blue phosphorene at high density. In particular, a trigonal nanoribbon-like phase is observed with the confinement of the BP-like chains. The comprehensive understanding of the evolution of the elemental allotropes in low dimension could provide fundamental guidance for the construction of polymorphic quantum materials with novel functionalities.

Automated summary

This study investigates the competition mechanism among a series of 0D-2D allotropes during adsorption, using low-dimensional phosphorus (P) as a prototype. The study finds that the formation of allotropes is significantly influenced by bond angle, coordination number, and atomic density. The comprehensive understanding of the evolution of elemental allotropes in low dimensions could guide the construction of polymorphic quantum materials with novel functionalities.