A simple descriptor for binding and charge transfer at blue phosphorene-metal interfaces

Abstract

We have performed density functional theory calculations to study the binding and charge transfer at interfaces between blue phosphorene and various metal substrates. The substrates considered are Al(111), Ag(111), Au(111), Pt(111), Zr(0001) and Sc(0001). The substrates suitable for use for synthesis and exfoliation of blue phosphorene, or instead for use as electrodes for either making contacts or charge doping blue phosphorene, are identified. We find that both the charge transfer and strength of binding correlate excellently with a simple descriptor D = Δ χ / Δ R , where Δ χ is the difference in Pauling electronegativities between the metal and phosphorus, and Δ R the corresponding difference in covalent radii. The predictions of the descriptor are validated by subsequent calculations on Pd(111), Cu(111) and Ir(111) substrates. This easily computed descriptor should help in the rapid identification of two-dimensional material + metal combinations suitable for specific applications. • We study interfaces between blue phosphorene and various metal substrates using density functional theory caalculations. • We formulate a descriptor = Δχ/Δℛ, where Δχ and Δℛ are the differences in electronegativities and atomic sizes respectively. • This descriptor can be used to predict both the charge transfer and the strength of binding at the interface.