Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-1, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
Adv Mater. 2018 Oct;30(43):e1804547. doi: 10.1002/adma.201804547. Epub 2018 Sep 14.
Halide perovskites, including CsPbX (X = Cl, Br, I), have gained much attention in the field of optoelectronics. However, the toxicity of Pb and the low photoluminescence quantum yield (PLQY) of these perovskites hamper their use. In this work, new halide materials that meet the requirements of: (i) nontoxicity, (ii) high PLQY, and (iii) ease of fabrication of thin films via the solution process are explored. In particular, copper(I) halide compounds with low-dimensional electronic structures are considered. Cs Cu I has a 0D photoactive site and exhibits blue emission (≈445 nm) with very high PLQYs of ≈90 and ≈60% for single crystals and thin films, respectively. The large exciton binding energy of ≈490 meV explains well the 0D electronic nature of Cs Cu I . Blue electroluminescence of Pb-free halides is demonstrated using solution-derived Cs Cu I thin films.
卤化物钙钛矿，包括 CsPbX（X=Cl、Br、I），在光电领域受到广泛关注。然而，Pb 的毒性以及这些钙钛矿的低光致发光量子产率（PLQY）限制了它们的应用。在这项工作中，我们探索了满足以下要求的新型卤化物材料：（i） 无毒，（ii） 高光致发光量子产率，（iii） 通过溶液法易于制备薄膜。特别地，考虑了具有低维电子结构的铜（I）卤化物化合物。CsCuI 具有 0D 光活性位点，表现出蓝色发射（≈445nm），单晶和薄膜的光致发光量子产率分别高达 ≈90%和 ≈60%。约 490meV 的大激子结合能很好地解释了 CsCuI 的 0D 电子性质。使用溶液衍生的 CsCuI 薄膜实现了无铅卤化物的蓝色电致发光。
