Highly Effective Work Function Reduction of α‐Borophene via Caesium Decoration: A First‐Principles Investigation

Abstract Borophene‐based nanocomposite is envisioned as a highly promising electrode material for nanoscale electronic devices such as light‐emitting diodes, organic solar cells, and field emitters. Therefore, engineering the work function of borophene to an optimal value is crucial for maximizing both conversion efficiency and device performance. A first‐principles density functional theory is employed to investigate the effects of Cs decoration on the structure, electronic properties, and work function of α‐borophene. The results indicate that Cs decoration effectively reduces the work function of α‐borophene (4.16 eV) to 3.05–0.11 eV at varying Cs concentrations, superior to those obtained in previous studies for Li (or other metal atom) decoration. Notably, work functions of all (but one) optimized Cs‐decorated α‐borophene configurations are lower than those of the commonly used electrode materials, Mg and Ca. Additionally, this study comprehensively investigates factors contributing to the work function reduction of Cs‐decorated α‐borophene relative to α‐borophene. Further, the results indicate that Cs decoration is a simple and effective method for decreasing the work function. Therefore, Cs‐decorated α‐borophene nanomaterials can be potentially utilized as cathode materials in electronic devices due to their metallic character and extremely low work functions.