Anomalous thermal quenching of Ca2-xGe7O16:xMn2+ orange-emitting phosphors

Abstract

The anomalous thermal quenching of phosphors maintains good luminescence properties at higher temperatures, which is great significant in the application of phosphors. Here, Ca_2-xGe₇O₁₆:xMn²⁺ phosphor has been synthesized by a solid sintering method. The luminescence properties of Ca_2-xGe₇O₁₆:xMn²⁺ is studied systematically It produce a broad spectrum emission around 600 nm under 222-nm ultraviolet excitation, with a maximum emission intensity as the concentration x = 0.015. The fluorescence lifetime decreased from 9.4 to 8.0 ms, with Mn²⁺ increasing from 0.005 to 0.03. The most interesting phenomenon is that the emission increases first and then decreases with temperature growing up. The maximum emission is 113% at 100 °C of that at room temperatures. The intensity is 101% as the temperature is 150 °C. The excellent thermal stability is very useful in the application.