Enhancing the ambient stability of few-layer black phosphorus by surface modification

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Few-layer black phosphorus (BP) is a promising material with unique electronic properties.
• However, BP is susceptible to oxidation, limiting its practical applications.
• Surface modification is a potential strategy to enhance BP's ambient stability.

Purpose of the Study:

• To investigate the adsorption characteristics of various elements on few-layer BP.
• To identify elements that can stabilize BP against oxidation.
• To propose a method for enhancing the practical applicability of few-layer BP.

Main Methods:

• High-throughput density functional theory (DFT) calculations were employed.
• Adsorption energies (Eads) and cohesive energies (Ecoh) were calculated for numerous elements.
• Elements were screened using the criterion Eads/Ecoh > 1.

Main Results:

• Fifteen elements were identified as suitable adsorbates based on the screening criterion.
• Adsorption of these elements significantly shifted the conduction-band minimum (CBM) of few-layer BP downwards.
• This downward shift suggests a potential to prevent BP oxidation by lowering the CBM below the O2/O2- redox potential.

Conclusions:

• Surface modification with specific elements can effectively enhance the ambient stability of few-layer BP.
• The identified elements offer a pathway to overcome the oxidation barrier for practical BP applications.
• This study provides an efficient approach for the rational design of stable black phosphorus-based devices.