Abstract In this work, under excitation at 808 nm, not only an unusual dominant emission of 2I11/2 → 4I15/2 transition (1.0 μm) but also the relatively weaker 1.55 μm luminesce (2I13/2 → 4I15/2) of Er3+ ions are observed with multi-phonon process and optical bistability behavior simultaneously for the first time. The bistability loops exhibit uniformly clockwise cycle characterized by a relatively lower trace of emission intensity at decreasing pump power. The result show that the looping behavior of NIR emissions has been found to be related to the 808 nm excited multi-photon band transition of BiOCl. Temperature sensing behavior of Er3+ indicate that such bistability effect is associated with thermally enhanced nonradiative decay and reduced luminescence quantum yield due to the strong pump-induced local thermal loading. This work may offer a novel insight into the transition behavior of lanthanides in layered semiconductors and promote the potential applications in optical switchers and temperature sensing.

中文翻译：

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在 Er3+ 单掺杂 BiOCl 层状半导体中具有循环机制和本征双稳态的 808 nm 激发多波段 NIR 发射

摘要 在这项工作中，在 808 nm 激发下，不仅 2I11/2 → 4I15/2 跃迁 (1.0 μm) 的异常主要发射而且相对较弱的 1.55 μm 发光 (2I13/2 → 4I15/2) Er3+ 离子首次同时观察到多声子过程和光学双稳态行为。双稳态回路呈现均匀的顺时针循环，其特征是在泵浦功率下降时发射强度的轨迹相对较低。结果表明，已发现 NIR 发射的循环行为与 BiOCl 的 808 nm 激发多光子带跃迁有关。Er3+ 的温度传感行为表明，这种双稳态效应与热增强的非辐射衰变和由于强泵诱导局部热负载导致的发光量子产率降低有关。