Thermochromic Luminescent Nanomaterials Based on Mn(4+)/Tb(3+) Codoping for Temperature Imaging with Digital Cameras

[Image: see text] A new thermographic nanocrystalline Sr(4)Al(14)O(25):Mn(4+),Tb(3+) phosphor was developed, and the concentrations of both dopants and the synthesis conditions were optimized. The combination of the thermally quenched luminescence from the Mn(4+) ions to the almost temperature-independent emission from Tb(3+) provides a sensitive luminescent thermometer (S(R) = 2.8%/°C at 150 °C) with strong emission color variability. In addition, a figure of merit for this luminescence thermochromism was proposed, as the relative sensitivities of the x and y CIE coordinates, which for this phosphor reaches at 150 °C S(R)(x) = 0.6%/°C and S(R)(y) = 0.4%/°C, respectively. Noncontact thermal imaging was demonstrated with this phosphor using a single consumer digital camera and exploiting the ratio of red (R) and green (G) channels of the RGB images, thereby confirming the high application potential of Sr(4)Al(14)O(25):Mn(4+),Tb(3+) nanocrystals for thermal sensing and mapping.