Synthesis and characterization of gadolinium vanadate matrix triply doped with lanthanide ions (Eu3+, Er3+, and Yb3+) by non-hydrolytic sol-gel

We report a gadolinium vanadate (GdVO4) matrix doped with lanthanide ions (Eu3+, Er3+, and Yb3+) prepared by the non-hydrolytic sol-gel methodology. The GdVO4 matrix doped with Eu3+, Er3+, and Yb3+ absorbs in the ultraviolet and infrared regions and emits in the visible and infrared regions. Due to the f -> f transitions of the lanthanide ions, the excitation spectra display a broad band in the UV region, as well as narrow bands. The emission spectra present bands in the visible and infrared regions. Upon excitation at the charge transfer band attributed to VO(4)(3-)and at the wavelength ascribed to charge transfer between Er3+ and Yb3+ in the infrared region, Eu3+ emits mainly in the visible region. The energy up-conversion spectra show bands in the green region, ascribed to Er3+, and red region, assigned to Eu3+. Structural characterization showed the GdVO4 tetragonal phase, space group I41/amd. The GdVO4 matrix doped with Eu3+, Er3+, and Yb3+ is a candidate for application in photovoltaic cells for absorption of ultraviolet and infrared radiation with consequent emission in the visible, red (Eu3+) and green (Er3+), and infrared regions (Er3+ and Yb3+), so that all the solar spectrum is used.