Halide perovskites, including CsPbX₃ (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. Cs₃Cu₂I₅ 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 Cs₃Cu₂I₅. Blue electroluminescence of Pb‐free halides is demonstrated using solution‐derived Cs₃Cu₂I₅ thin films.

中文翻译：

---

电子结构为0D的无铅高效蓝光Cs3Cu2I5

卤化物钙钛矿，包括CsPbX ₃（X = Cl，Br，I），在光电子学领域引起了广泛关注。但是，这些钙钛矿的Pb毒性和低光致发光量子产率（PLQY）妨碍了它们的使用。在这项工作中，探索了满足以下要求的新型卤化物材料：（i）无毒，（ii）高PLQY和（iii）通过溶液法易于制造薄膜。特别是考虑了具有低维电子结构的卤化铜（I）化合物。Cs ₃ Cu ₂ I ₅具有一个0D光敏位点，并表现出蓝色发射（≈445nm），单晶和薄膜的PLQY分别非常高，分别约为≈90％和≈60％。≈490meV的大激子结合能很好地解释了Cs ₃ Cu ₂ I ₅的0D电子性质。使用溶液衍生的Cs ₃ Cu ₂ I ₅薄膜证明了无铅卤化物的蓝色电致发光。