Zn₂GeO₄ nanowires as efficient electron injection material for electroluminescent devices

Pure phase Zn₂GeO₄ nanowires (NWs) were grown by the chemical vapor transport method on p-GaN: Mg/Al₂O₃ substrate. The as-grown Zn₂GeO₄ NWs exhibited n-type characteristic due to native defects and formed a p-n heterojunction with the p-GaN substrate. The unique energy level of Zn₂GeO₄ NWs promotes electron injection into GaN active region while suppressing hole injection into Zn₂GeO₄ NWs. The device exhibited an emission centered at 426 nm and a low turn-on voltage around 4 V. Zn ₂GeO₄ NWs are first reported in this paper as promising electron transport and injection material for electroluminescent devices.