First-principles study on electronic properties of different activation mechanisms on AlGaN nanowire photocathodes surface.

In this study, structural, stability and electrical properties of Al 0.5 Ga 0.5 N nanowires are analyzed in detail under different Cs activation conditions including the activation of Cs, Cs/O, and Cs/NF 3 based on first principles and density functional theory (DFT). It is proved that Cs/NF 3 adsorption provides superior structural stability and lower work function compared to Cs adsorption alone, which significantly improves photoelectric response and quantum efficiency, especially at high Cs coverage. In addition, Cs adsorption is affected by adsorption saturation at high Cs coverage, but 3Cs/NF 3 model exhibits a more stable and persistent low-work function, which effectively mitigates the negative effects of Cs saturation. And the variation of average dipole moment of 3Cs/O and 3Cs/NF 3 activated nanowires coincides with decrease of work function. • Structural, stability and electrical properties of activated Al 0.5 Ga 0.5 N nanowires are analyzed in detail. • 3Cs, 3Cs/O and 3Cs/NF 3 activated models are crucial for understanding photovoltaic performance of Al 0.5 Ga 0.5 N NW. • For 3Cs/O and 3Cs/NF 3 activated nanowires, variation of average dipole moment coincides with decrease of work function. [ABSTRACT FROM AUTHOR]