Abstract:

Vanadium dioxide is a well-known near room temperature phase transition material with a transition temperature (tau(C)) at 68 degrees C. In this paper, Eu3+ dopant with different doping levels was introduced into the crystal lattice of VO2. The thermochromic properties, including the integrated visible transmittance (T-lum) and the solar modulating ability (Delta T-sol) were favorably affected by the Eu-doping. It is of great interest that the substitution of V4+ by Eu3+ in the VO2 crystal structure reduced the tau(C) from 68 degrees C to 47.5 degrees C with an approximate decreasing rate of 6.5 degrees C/at% up to 4 at%. More importantly, the Eu dopant helped in improving the properties of luminous transmittance and solar modulating ability, which were difficult to be achieved by other dopants.