Visible photon avalanche up-conversion of Yb(3+) and Ho(3+) doped NaBi(WO(4))(2) phosphors under excitation at 980 nm

Avalanche phenomenon uses critical pump power to produce extreme nonlinear behavior from small disturbances, and has gradually become known. Here, it is reported that the strong green up-conversion emission produced in NaBi(WO(4))(2) phosphor by the positive feedback enhancement of the energy transfer process. The power dependence indicates that the photon avalanche process has occurred. Contrary to other up-conversion mechanisms, photon avalanche (PA) is a bifurcation phenomenon: avalanches occur above the critical excitation power. The experimental results are analyzed using the rate equation model. The high-response photon avalanche process produced by Yb and Ho ions is discussed in detail. The results show that PA can not only improve the brightness and efficiency of up-conversion, but also has a wider range of applications than traditional up-conversion materials, especially in the detection material of temperature sensor plays an important role.