Enhanced Stability of Black Phosphorus Field-Effect Transistors via Hydrogen Treatment

Atomically thin black phosphorus (BP) exhibits great potential for wide applications in future electronic and optoelectronic devices. However, BP exhibits fast ambient degradation and is thus severely limited in practical applications. Here, a simple strategy using hydrogen treatment to enhance the environmental stability of BP flakes is reported. Owing to the drastically suppressed ambient degradation by hydrogen treatment, atomic BP flakes are just slightly corroded on the surface even after up to 4 weeks in air, and more impressively, the BP field-effect transistors still maintain over 85% of their initial mobility and I_ON/I_OFF ratio. First-principle calculations indicate that the hydrogen molecules are probably embedded between BP layers, and shift down the conduction band minimum, which strongly protects against the formation of superoxide on the surface and thus suppresses the ambient degradation of BP. This study provides a simple and nondestructive route to achieve air-stable BP devices.