Solar Radiation Conversion With Mesoporous Silica Activated by Rare-Earth Ions

Intrinsic and extrinsic nature of the luminescence of pure and Eu3+ and Tb3+ rare-earth ions activated mesoporous silica has been investigated by spectroscopic methods. Increasing the Eu3+ impurity concentration from 0.01 mg to 7 mg, results in an increase of the impurity particles radiation in the luminescent mesoporous colloidal silica (LMCS) matrix by several times. With an increase in the concentration of Tb3+ from 0.01 mg to 3 mg, impurity luminescence intensity increases several times while the intrinsic luminescence intensity maximum at 400 and 460 nm is decreasing. Based on the experimental evidence, it is suggested that the energy of the own electronic matrix excitation is transferred by emitters, i.e., impurities of Eu3+ and Tb3+ ions. Also, it is assumed that the emission band at 610 nm in an LMCS—Eu3+ and emission band at 543 nm in the LMCS—Tb3+ is attributed to the intracenter transitions within the Eu3+ and Tb3+ ions.