Photoluminescence characteristics and white light generation in borohydride derived co-doped (Eu3+, Tb3+) YBO3 phosphors

The prime theme of this work is to explore the excitation wavelength dependent photoluminescence characteristics and white light generation in activators [europium (Eu) and terbium (Tb)] doped yttrium borate (YBO3) phosphors. In order to study the influence of excitation wavelength on photoluminescence emission intensity, a fixed amount (5 mol%) of Tb and different concentration of Eu (1, 2, 3, 5 and 7 mol%) were co-doped into yttrium borate (YBO3) host matrix via a solution precursor route using sodium borohydride as a precipitating agent. The ratio of Tb and Eu emission peaks suggests that it is possible to produce multi-color emissions including white light. The excitation dependence of emission comes from the combined contribution of host, activator and energy transfer between host to activator as well as among individual activators, which gives rise to change in output emission color. Moreover, the optimum composition i.e. 3 mol% Eu, 5 mol% Tb co-doped YBO3 was found to be appropriate for white light emitting phosphor.