Ultrapure Green Light Emission in One-dimensional Hybrid Lead Perovskite: Achieving Recommendation 2020 Standard

An ultrapure green phosphor with narrow emission range (525–535 nm) and full width at half maximum (FWHM < 25 nm) is critical for a backlit light-emitting diode to realize an ultrawide color gamut in liquid-crystal display (LCD), according to the Rec. 2020 standard. However, it is extremely formidable to achieve this goal for low-dimensional halide perovskites (LDHPs), which readily display broadband emissions arising from self-trapped excitons due to strong electron–phonon coupling. Herein, we report a new one-dimensional (1D) hybrid lead halide of [TMPDA]2Pb3Br10 (TMPDA = tetramethyl-1,3-diaminopropane) displaying unusual ultrapure green light emission. Benefiting from the synergistic work of weak electron–phonon interaction and strong quantum confinement, this 1D halide displays sharp green emission at 526 nm with narrow FWHM (25 nm), high photoluminescence quantum yield (71.95%) and color purity (91.1%), which achieves the Rec. 2020 standard and represents the purest green emitting LDHP to date. Remarkably, as a down-conversion green phosphor, [TMPDA]2Pb3Br10 provides an ultrawide color gamut covering 121.5% of NTSC and 90.7% of Rec. 2020 standards, showcasing the application in high-resolved LCD. The establishment of a fundamental structure–property relationship also paves a new way to rationally design novel narrow-band emitting LDHPs as a supplement of colloidal 3D perovskite nanostructures.