Upconversion metal (Zr, Hf, and Ta) oxide aerogels.

A major obstacle in developing upconversion aerogels is the incompatibility of the highly-developed porosity and the crystal structure required for converting light to a shorter wavelength. We propose a novel method for creating a sol-gel procedure for synthesizing metal (Zr, Hf, and Ta) oxide upconverison aerogels uniformly doped with Er3+ and Yb3+ by precisely adjusting the calcination conditions.