High-performance large-area quasi-2D perovskite light-emitting diodes

• Published in: Nature communications Vol. 12; no. 1; p. 2207
• Main Authors: Sun, Changjiu, Jiang, Yuanzhi, Cui, Minghuan, Qiao, Lu, Wei, Junli, Huang, Yanmin, Zhang, Li, He, Tingwei, Li, Saisai, Hsu, Hsien-Yi, Qin, Chaochao, Long, Run, Yuan, Mingjian
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.04.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005; 639/624/1020; Crystallization; Enthalpy; Fabrication; Failure mechanisms; Humanities and Social Sciences; Light emitting diodes; multidisciplinary; Perovskites; Recombination; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-22529-x

Serious performance decline arose for perovskite light-emitting diodes (PeLEDs) once the active area was enlarged. Here we investigate the failure mechanism of the widespread active film fabrication method; and ascribe severe phase-segregation to be the reason. We thereby introduce L-Norvaline to construct a COO − -coordinated intermediate phase with low formation enthalpy. The new intermediate phase changes the crystallization pathway, thereby suppressing the phase-segregation. Accordingly, high-quality large-area quasi-2D films with desirable properties are obtained. Based on this, we further rationally adjusted films’ recombination kinetics. We reported a series of highly-efficient green quasi-2D PeLEDs with active areas of 9.0 cm 2 . The peak EQE of 16.4% is achieved in <n  > = 3, represent the most efficient large-area PeLEDs yet. Meanwhile, high brightness device with luminance up to 9.1 × 10 4  cd m −2 has achieved in = 10 film. Performance of perovskite LED tends to decline as the active area increases, thus understanding the failure mechanism is paramount to surmount this limitation. Here, the authors report severe phase-segregation to be the cause, and introduce L-Norvaline to overcome it, as the result, highly-efficient 9.0 cm 2 green PeLED is realised.