Modulating the Rise and Decay Dynamics of Upconversion Luminescence through Controlling Excitations

Abstract

AbstractDifferent from organic dye/quantum dot possessing one luminescent center, upconversion luminescence (UCL) is actually a statistic of temporal behaviors of countless individual activators. Our experimental results have shown that the rise and decay dynamics of UCL is directly associated with the relative contribution of sensitizer‐to‐activator energy transfer and energy migration among sensitizers, which can be physically modulated by simply tuning the excitation laser. Therefore, dynamic UCL with record‐wide 20‐fold lifetime, ≈70‐fold red‐to‐green intensity ratio, and reversibly definable emission color is easily realized by just modulating the excitation laser. Moreover, this generally applicable strategy only requires a simplest‐possible UCL system whereas prevalent material engineering such as complicated composition design, sophisticated core–shell construction, or tedious chemical synthesis, is no longer needed.