A novel red emitting phosphor KSrY 1-x (BO 3 ) 2 : xRE (RE=Sm 3+ , Eu 3+ ) for white light emitting diode: synthesis and optical properties

In the present work, a series of Eu3+ and Sm3+ doped KSrY(BO3)2 phosphor were synthesised using the solution combustion technique. The crystal structure, surface morphology, functional properties and luminescent properties of phosphor were investigated using XRD, SEM, FTIR spectroscopy and Photoluminescence analysis, respectively. The optical band gap of synthesised phosphor was estimated using ultra-violet diffuse reflectance spectroscopy (UV-DRS). The influence of doping concentration of Eu3+ on its relative emission intensity and critical distance of energy transfer was systematically investigated. At 405 nm excitation, the Sm3+ shows a strong emission peak at 600 nm in the reddish-orange region due to the electric dipole transition 4G5/2→6H7/2 of Sm3+ ion. The Eu3+ emission in KSrY(BO3)2 consists of the transitions from 5D0→7FJ (J = 0, 1, 2, 3), and the excitation spectrum consists of a broad excitation band peaking at 394 nm and some intense narrow lines. All the obtained results indicates that the synthesised phosphor KSrY(BO3)2:Eu3+, Sm3+ phosphor are effectively excited with near-UV and VUV light of 394 and 405 nm, respectively, and has potential for NUV excited pc-WLED’s and solid-state lightning applications.