Far‐Red‐Emitting BiOCl:Eu 3+ Phosphor with Excellent Broadband NUV ‐Excitation for White‐Light‐Emitting Diodes

Rare‐earth ion‐doped semiconducting phosphor has attracted extensive attention due to the ability to achieve efficient luminescence through the host sensitization. Here, we present a new type red‐emitting Eu 3+  ‐doped BiOCl phosphors possessing a broad excitation band in the near‐ultraviolet ( NUV ) region. Experimental measurements and theoretical calculations confirm that Eu 3+ ion dopants result in forming impurity energy level near valence band, and the excellent broadband NUV ‐exciting ability of Eu 3+ ion is due to the electronic transitions of BiOCl band gap. Moreover, the highest emission intensity of the phosphors is from the 5 D 0 → 7 F 4 transition of Eu 3+ around 699 nm (far‐red) through whether host excitation or direct Eu 3+ ions excitation, which lie in the particular structure of BiOCl crystals. Our results indicate that the Eu 3+  ‐doped BiOCl crystals show great potential as red phosphors for white‐light‐emitting diodes.