Nanoscale heterophase regulation enables sunlight-like full-spectrum white electroluminescence

Traditional white light-emitting diodes operate by exciting phosphors using blue light-emitting diodes, leading to the absence of specific colour bands compared with the visible light region of the sunlight spectrum (400–780 nm), and excess blue light increases the risk of harmful effects on ecosystems and organisms. Here, we precisely design and regulate heterophase γ/δ-CsPb(I/Cl)3 at the nanoscale for uniform heterophase distribution, balanced flow of charges and tunable spectrum. Then, γ/δ-CsPb(I/Cl)3 directly excited by electricity shows full-spectrum white electroluminescence covering 400–780 nm with standard Commission Internationale de l’Eclairage coordinates of (0.33, 0.33), a Colour Rendering Index of 95, a Correlated Colour Temperature of 5829 K and a Delta u,v of −3 × 10−4, accompanied with balanced white light composition (Melanopic ratio = 1.004). The match indices of such five core indicators to standard sunlight reach 100%, 95% (97% for R9), 99.5%, 99.97% and 99.6%, respectively, far ahead of as-fabricated commercial white light-emitting diodes.