Two-dimensional few-layered Janus diamond nanofilms with boron-terminated surfaces: First-principles calculation

In this work, the structural and electronic properties of two-dimensional (111) diamond nanofilms with a layer number of n = 3-6 are investigated by first-principles calculation. Two kinds of Janus models (both-side boron-termination model, one-side hydrogenation and another-side boron termination model) are dynamically and thermally stable. The nanofilms have direct bandgap characteristic, and their bandgaps are tunable in a region of 2.0 - 2.7 eV. The reduced bandgaps are mainly related to the surface termination of boron atoms. Interestingly, the electron mobilities (1500 cm(2).V-1.s(-1)) are higher than their hole mobilities (<660 cm(2).V-1.s(-1)) for both models under various film thickness. The Janus structures are favorable to realize high-performance photocatalysis devices in the visible region.

Automated summary

This study examines the structural and electronic properties of two-dimensional (111) diamond nanofilms with a layer number of n = 3-6 through first-principles calculations. It finds that Janus structures with direct bandgap characteristics and tunable bandgaps are dynamically and thermally stable. Interestingly, these structures exhibit higher electron mobilities compared to hole mobilities, making them favorable for high-performance photocatalysis devices in the visible region.