Visible quantum cutting via downconversion in a novel green-emitting K2Gd(WO4)(PO4):Tb3+ phosphor

• A novel phosphor K2Gd(WO4)(PO4):Tb was successfully synthetized via a solid-state reaction.
• The crystal structure of KGWP as a new host matrix was defined.
• Visible quantum cutting has been identified in KGWP:0.5Tb3+ system.
• CTQE is 183.2% and 176.4% for excitation at 235 and 150 nm.
• KGWP:0.5Tb3+ can be a potential candidate for 3D-PDPs and Hg-free lamps.

A novel phosphor K2Gd(WO4)(PO4):Tb was prepared via a solid-state reaction. The crystal structure of K2Gd(WO4)(PO4) as a new host matrix for luminescence was defined to be the orthorhombic system with space group Ibca (73). Visible quantum cutting under Tb3+ 4f8–4f75d1 excitation and host excitation in K2Gd(WO4)(PO4):Tb3+ via a downconversion was identified. In order to rationalize the quantum cutting effect, the proper mechanism was proposed. According to calculations, the quantum efficiency was up to 183.2% and 176.4% under excitation at 235 nm and 150 nm, respectively. When compared with Zn2SiO4:Mn2+ (P1-G1S), KGWP:0.5Tb3+ is slightly less bright over 450–650 nm but has a shorter decay time.