Luminescence characteristics and optimization of (La,Gd)Sr2(Al,B)O5:Ce phosphor for white light emitting diodes

► High luminescence (La,Gd)Sr2(Al,B)O5:Ce yellow phosphor was prepared for LED application. ► Luminescence properties were optimized by changing the content of Gd and B substituent. ► A red shift in the emission was observed by the substitution of Gd3+ and B3+ ions. ► The red shift was due to the lattice shrinking for Gd3+ and the increase of lattice covalency for B3+. ► The optimized sample had about 368% improved emission intensity compared with LSA:Ce.