Simultaneous luminescence in Ⅰ, Ⅱ and III biological windows realized by using the energy transfer of Yb3+ → Er3+/Ho3+ → Cr3+

Until now, the emissions of most biological phosphors were located at a single biological window. By utilizing energy transfer of Yb3+ → Ln3+ → Cr3+, we have successfully developed a phosphor emitting in the first, second and third biological windows simultaneously. The luminescences have good thermal stability because of forming the thermal cycle among Ho3+ and Cr3+. And temperature measurement can be realized in NIR-3.