The Structureand Luminescence Properties Of BCNO Materials Prepared By Sintering Of The Precursor

In this paper, BCNO phosphors were prepared based on the reaction of trimethyl borate(B source), melamine (N source), formaldehyde and methenamine by sintering of theprecursor. We studied the effects of process conditions and ion doping on the structure andluminescence properties of BCNO materials.In the process condition experiments, the effects of B/N source mole ratio, the content ofcarbon source, the different carbon source, sintering conditions on the structure andluminescence properties of BCNO phosphors were investigated. XRD, FTIR and PL resultsshowed that the preparation conditions changed the element composition and the types ofchemical bonds in BCNO phosphors, and affected the luminescence properties. Themaximum quantum efficiency of BCNO can reach65.2%. When the B/N source ratio andthe content of carbon source increased, the emission peaks of BCNO phosphor red-shiftedand the emission intensity reduced. The effects of carbon source (glycol, ethylene diamineand oxalic acid) with similar carbon chain structure and different surface functional groups(-OH,-COOH,-NH2) on luminescence properties were investigated. Among them, whenethylene diamine was used as carbon source, BCNO had maximum emission peak position(545nm) in the same excitation condition, and the precursor can emit blue light under ultraviolet excitation. In addition, the emission peaks of BCNO phosphors blue-shifted withincreasing the sintering time and temperature.In ion doping experiments, the effects of anion doping (F–, Cl–) and cation doping (Li+,Na+, K+, Mn2+, Al3+, Ti4+) on the structure and luminescence of BCNO phosphors wereinvestigated. For the anion doping, taking F–doping for example, F was not detected fromXPS and FTIR spectra. However, the surface of samples was corroded seriously, and theemission peaks of BCNO were red-shifted with increasing NH4F. For the cation doping, theemission peaks of BCNO, as a whole, were blue-shifted with increasing doping contents.For monovalent cations doping (Li+, Na+, K+), the excitation peak at370nm wasblue-shifted, the emission spectra became asymmetric and the color of the samples changedfrom yellow to white with increasing doping ions. For bivalent cation doping (Mn2+), whenthe doping content increased, the PL intensity was decreased and a shoulder emission peak appeared at long wavelength. For trivalent cation doping (Al3+), BCNO phosphors’luminescence intensity increased with increasing doping concentration.