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Lead‐Free Highly Efficient Blue‐Emitting Cs 3 Cu 2 I 5 with 0D Electronic Structure
Author(s) -
Jun Taehwan,
Sim Kihyung,
Iimura Soshi,
Sasase Masato,
Kamioka Hayato,
Kim Junghwan,
Hosono Hideo
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201804547
Subject(s) - halide , photoluminescence , materials science , electroluminescence , quantum yield , thin film , exciton , optoelectronics , luminescence , copper , nanotechnology , photochemistry , inorganic chemistry , optics , physics , chemistry , condensed matter physics , fluorescence , metallurgy , layer (electronics)
Halide perovskites, including CsPbX 3 (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 3 Cu 2 I 5 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 3 Cu 2 I 5 . Blue electroluminescence of Pb‐free halides is demonstrated using solution‐derived Cs 3 Cu 2 I 5 thin films.