Giant efficiency and color purity enhancement in multicolor inorganic perovskite light-emitting diodes via heating-assisted vacuum deposition

• Published in: Journal of semiconductors 2020-05, Vol.41 (5), p.52205-104
• Main Authors: Han, Boning, Shan, Qingsong, Zhang, Fengjuan, Song, Jizhong, Zeng, Haibo
• Format: Article
• Language: English
• Subjects: all-inorganic perovskites; color purity; CsPbBr; heating assisted vacuum deposition; light-emitting diodes
• ISSN: 1674-4926; 2058-6140
• DOI: 10.1088/1674-4926/41/5/052205

Inorganic perovskites (CsPbX3 (X = I, Br, Cl)) have broad prospection in the field of high-definition displaying due to its excellent optoelectronic characteristics. The vacuum deposition process possesses advantages and competitiveness in the industrialized production. However, the performance of light emitting diodes (LEDs) based on vacuum-deposited is incredibly low. Herein, we proposed a heating-assisted vacuum deposition (HAVD) method to construct inorganic perovskite LEDs (PeLEDs) with enhanced performance. The roughness and crystallinity of perovskite film were improved by regulating the heating treatment of substrates. And the perovskite film exhibited largely rise in luminescence, with decreasing defect density. Consequently, with the optimized temperature, the green PeLEDs exhibited 100-fold improvement of external quantum efficiency (EQE) with the luminance of up to 11 941 cd/m2, and the full width at half-maximum (FWHM) of the electroluminescence (EL) spectra was decreased from 25 to 17 nm. At the same time, the red and blue PeLEDs also exhibited obvious enhancement in EQE and luminance by HAVD method, and both the FWHM of EL spectra dropped below 20 nm, exhibiting excellent high color purity. HAVD strategy has a huge potential to be a new commonly used method for low-cost fabrication of displays and lighting.