White wide-band emission from Yb$^{3+}$:Y$_{2}$Si$_{2}$O$_{7}$ nanoparticles under IR excitation*

The spectral properties of Yb$^{3+}$~ions have attracted considerable attention and offered the possibility of obtaining an infrared emission and an up-converted emission. The emission properties of various host media activated with Yb$^{3+}$, have been recently studied even in nanoscale form, due to their potential photonic application. Ytterbium (Yb$^{3+})$ doped Y$_{2}$Si$_{2}$O$_{7}$ powders with average particle size 40 were successfully synthesized using the sol-gel technique. At the pressure of 0.01 mbar a wide white light band appeared. The International Commission on Illumination (CIE) coordinates (c) using an illuminance meter for nano-particles at a distance of 5cm. The CIE coordinates were found to be (0.465, 0.377) for white emission under 950~nm excitation.