The self-activated K₇CaY₂(B₅O₁₀)₃ phosphor and the effect of trivalent dopants on the emission properties

In recent years, several new borate compositions have been investigated. Optical properties of these new borates have been studied for some applications like self-frequency doubling and solid state lighting. In this context, Ultraviolet A (UVA) luminescence of Bi[Formula: see text] in K 7 CaY 2 (B 5 O[Formula: see text] has been reported and assigned to Bi[Formula: see text]S[Formula: see text]P 1 transitions. However, we discovered similar emissions from the host devoid of Bi[Formula: see text] or any other (lanthanide) dopant. Considering the transparency of the host, this cannot be due to bandgap luminescence or edge emission. We have attributed the luminescence to lattice defects. This conclusion is consistent with similar literature results on other borates, e.g., YBO 3 . The effect of codoping on this defect-related emission is studied. Whatever the source of UV luminescence which is in UVA region, one can find several uses for this. By virtue of UVA emission, phosphor may be useful for several applications such as phototherapy treatments for skin diseases, insect and pest control and treating organic pollutants for safe disposal.