Ishii Ayumi, Miyasaka Tsutomu
Graduate School of Engineering, Toin University of Yokohama, Kanagawa, Japan.
J Chem Phys. 2020 Nov 21;153(19):194704. doi: 10.1063/5.0030596.
Quantum cutting is an attractive optical phenomenon where one high-energy photon is converted into two low-energy photons, resulting in photoluminescence quantum yields (PLQYs) above 100%. In this report, we demonstrate a novel approach to enhance the quantum cutting energy transfer from an all-inorganic perovskite (CsPbCl) to ytterbium (Yb) and erbium (Er) ions as near-infrared (NIR) emitters by using the highly orientated crystalline film. Yb ions are fixed in the neighborhood of the CsPbCl lattice by preparing a one-to-one layer arrangement consisting of quasi-2D CsPbCl perovskite and Yb layers. The successful preparation of layer arrangements resulted in the highly sensitized luminescence of Yb by CsPbCl with NIR PLQYs exceeding 130%, which is attributed to quantum cutting. In addition, Er luminescence at 1540 nm is acquired by the co-existence of Er with Yb in a layer, which is a result of the intralayer metal-to-metal energy transfer from Yb activated by CsPbCl via the interlayer quantum cutting process. The PLQY of Er luminescence reaches to 12.6%, which is the highest value ever observed for Er compounds, resulting from the efficient interlayer quantum cutting process over 100% and the following intralayer resonance metal to metal energy transfer with the efficiency over 80%.
量子剪裁是一种引人注目的光学现象，其中一个高能光子被转换为两个低能光子，从而产生高于100%的光致发光量子产率（PLQYs）。在本报告中，我们展示了一种新颖的方法，通过使用高度取向的晶体薄膜来增强从全无机钙钛矿（CsPbCl）到作为近红外（NIR）发射体的镱（Yb）和铒（Er）离子的量子剪裁能量转移。通过制备由准二维CsPbCl钙钛矿和Yb层组成的一对一单层排列，Yb离子被固定在CsPbCl晶格附近。层状排列的成功制备导致CsPbCl对Yb的高敏化发光，其近红外PLQY超过130%，这归因于量子剪裁。此外，通过在一层中Er与Yb共存获得了1540 nm处的Er发光，这是通过层间量子剪裁过程由CsPbCl激活的Yb发生层内金属到金属能量转移的结果。Er发光的PLQY达到12.6%，这是Er化合物中观察到的最高值，这是由于超过100%的高效层间量子剪裁过程以及随后效率超过80%的层内共振金属到金属能量转移。
