Blue emitting BCNO phosphors with high quantum yields

The blue emitting BCNO phosphors with high quantum yields were prepared at 625 degrees C using boric acid, melamine and hexamethylenetetramine as raw materials. The BCNO phosphors have turbostratic boron nitride structure and consist of nanocrystallites 5 nm in size. The emission and excitation spectra can be tuned by the contents of raw materials and sintering temperatures. The quantum yields of BCNO phosphors can be up to 99% with increasing boric acid. The FTIR spectra suggested that the quantum yield can be improved with increasing strength of B-N and B-N-B bonds, and formation of B-O-B bonds, while it decreased with enhancement of C=C bonds. The emission decay curves indicated that the decay process was related to two luminescence centers corresponding to carbon and oxygen impurities. In addition, the high temperature emission spectra disclosed that the nitrogen vacancy would participate in the blue light emission process at a certain heating temperature. The blue emitting BCNO phosphors with high quantum yields have great potential application in luminescence and display areas.