Upconversion luminescence mechanisms of Er3+-doped barium gallogermanate glasses
Er3+离子掺杂钡镓锗玻璃上转换发光机理研究

The absorption, Raman and upconversion luminescence spectra of Er3+-doped barium gallogermanate glasses have been measured and the upconversion mechanisms of Er3+-doped barium gallogermanate glasses have been analyzed. The absorption and Raman spectra show that barium gallogermanate glasses have the ultraviolet absorption edge of 275nm and the maximum vibrational energy of 828cm-1, respectively. Intense green and red emissions, excited by 800nm and 980nm laser diode, were observed at room temperature. With increasing Er3+ ion concentration, the green emission increases initially and then decreases, while the red emissions increases monotonicly. Under the excitation of 800nm laser diode, the green emission is mainly attributed to the excited state absorption from the 4I13/2 level and the red emission to the energy transfer between the 4I13/2 level and the 4I11/2 level. Under the 980nm laser diode excitation, the green emission mainly originates from the energy transfer between the 4I11/2 levels and the red emission from the energy transfer between the 4I13/2 and 4I11/2 levels as well as the excited state absorption of the 4I13/2 level. The calculation results of quantum efficiency for different pumping wavelengths show that the upconversion efficiency of the green emission in barium gallogermanate glass with 1mol% Er3+ ions reaches a maximum value under the excitation of 800nm laser diode.