Electron Injection of Phosphorus Doped g‐C3N4 Quantum Dots: Controllable Photoluminescence Emission Wavelength in the Whole Visible Light Range with High Quantum Yield

The large band gap (2.7 eV) of graphite‐like carbon nitride (g‐C 3 N 4 ) enables the g‐C 3 N 4 quantum dots (g‐C 3 N 4 QDs) to show near ultraviolet‐blue photoluminescence. This study demonstrates the effective band gap control of g‐C 3 N 4 QDs by phosphorus doping for the first time. With the electronic injection process of lattice doped P, the band gap decreased observably. The emission wavelength of phosphorus doped g‐C 3 N 4 QDs (P‐g‐C 3 N 4 QDs) can be tuned in whole visible light range (385–762 nm) by changing the doping concentration. Due to the direct band gap of these P‐g‐C 3 N 4 QDs, the quantum yield is higher than 0.90. The authors also show the application value of these P‐g‐C 3 N 4 QDs in both in vitro and in vivo fluorescent bio‐imaging.