Multivariate Analysis Identifying [Cu(N^N)(P^P)]⁺ Design and Device Architecture Enables First-Class Blue and White Light-Emitting Electrochemical Cells

White light-emitting electrochemical cells (LECs) comprising only [Cu(N^N)(P^P)]⁺ have not been reported yet, as all the attempts toward blue-emitting complexes failed. Multivariate analysis, based on prior-art [Cu(N^N)(P^P)]⁺-based thin-film lighting (>90 papers) and refined with computational calculations, identifies the best blue-emitting [Cu(N^N)(P^P)]⁺ design for LECs, that is, N^N: 2-(4-(tert-butyl)phenyl)-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridine and P^P: 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, to achieve predicted thin-film emission at 490 nm and device performance of 3.8 cd A⁻¹@170 cd m⁻². Validation comes from synthesis, X-ray structure, thin-film spectroscopic/microscopy/electrochemical characterization, and device optimization, realizing the first [Cu(N^N)(P^P)]⁺-based blue-LEC with 3.6 cd A⁻¹@180 cd m⁻². This represents a record performance compared to the state-of-the-art tricoordinate Cu(I)-complexes blue-LECs (0.17 cd A⁻¹@20 cd m⁻²). Versatility is confirmed with the synthesis of the analogous complex with 2-(4-(tert-butyl)phenyl)-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyrazine (N^N), showing a close prediction/experiment match: λ = 590/580 nm; efficiency = 0.55/0.60 cd A⁻¹@30 cd m⁻². Finally, experimental design is applied to fabricate the best white multicomponent host:guest LEC, reducing the number of trial-error attempts toward the first white all-[Cu(N^N)(P^P)]⁺-LECs with 0.6 cd A⁻¹@30 cd m⁻². This corresponds to approximately ten-fold enhancement compared to previous LECs (<0.05 cd A⁻¹@<12 cd m⁻²). Hence, this work sets in the first multivariate approach to design emitters/active layers, accomplishing first-class [Cu(N^N)(P^P)]⁺-based blue/white LECs that were previously elusive.