Near‐Unity PLQY of Cs₃Cu₂X₅ (X = Cl, Br) for High‐Efficiency White Light‐Emitting Diodes with Exceptional Color Quality

Metal halide perovskites and their derivatives have emerged as highly promising materials for next-generation optoelectronic devices, owing to their intrinsic defect tolerance and exceptional electrical and optical properties. Among these, lead-free copper(I)-based halide perovskite derivatives, Cs₃Cu₂X₅ (X = Cl, Br, I) (CHPs), have garnered significant attention as environmentally friendly and stable alternatives to lead-based perovskites. In this study, a cost-effective and sustainable synthesis route for Cs₃Cu₂Cl₅ and Cs₃Cu₂Br₅ powders is developed, which exhibit strong green (≈526 nm) and blue (≈458 nm) emissions, and achieve remarkable photoluminescence quantum yields (PLQYs) of 100% and 92%,…

• NS
  National Science Foundation

  Awards: ECCS‐1872846, DMR-1829070, ECCS-1872846, 1829070, 1-P30-GM124166-01A1, 2342336
• UO
  University of Missouri
• DF
  Directorate for Mathematical and Physical Sciences

  Awards: DMR‐1829070, DMR‐2342336
• NI
  National Institute of General Medical Sciences

  Awards: 1-P30-GM124166, 1‐P30‐GM124166‐01A1, 1-P30-GM124166-01A1, GM124166, DMR-1829070
• DO
  Division of Materials Research

  Awards: 2342336, DMR-1829070, DMR-2342336, 1829070
• DO
  Division of Electrical, Communications and Cyber Systems

  Award: 1872846