Fabrication of centimeter-scale MAPbBr₃ light-emitting device with high color purity

In this study, 3 cm × 3 cm organometallic halide perovskite (MAPbBr₃) nanocrystalline thin film and light-emitting diodes (LEDs) were synthesized and fabricated using a combined thermal evaporation and spin-coating technique. PEDOT:PSS(Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) and TPBi(2,2′,2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1- H-benzimidazole)) were used as the hole and electron transport layers for the LEDs, respectively. The structural, photophysical, electronic, and electroluminescent properties of the devices were measured and characterized. The p-i-n device showed a turn-on voltage of approximately 1.5 V, with electroluminescence centered at 535 nm at a full width at half maximum (FWHM) of 14 nm. The device displayed high color purity, an external quantum efficiency, and a maximum luminance of 100%, 1.86%, and 1610 cd/m², respectively. Results demonstrated the advantages of combining thermal evaporation and solution process in producing larger-area perovskite display and lighting devices.