Infrared detection by binary phosphides is of great interest due to their high carrier mobility, excellent stability, and high absorbance coefficient, as they have a wide range of applications in civil and military fields. As the only metastable phase in gold phosphide, Au₂P₃ has attracted great attention in fundamental research and optoelectronic applications. Here, we synthesized high-quality and environmentally stable Au₂P₃ nanosheets through a modified facile one-step mineralization-assisted chemical vapor transport method. Through systematic infrared photoluminescence characterizations, it is found that the as-synthesized Au₂P₃ nanosheets display an impressive mid-infrared luminescence band centered at about 6.64 μm (0.187 eV) at room temperature. Furthermore, Au₂P₃-based self-powered photodetectors display outstanding infrared detection performance with D^* = 2.9 × 10¹⁰ Jones at 1550 nm and D^* = 1.9 × 10⁸ Jones at 2611 nm, respectively. Our results suggest that the synthesized Au₂P₃ nanosheets could be promising candidates for future chip-based infrared nanophotonic and optoelectronic circuitry.