Efficient Ruddlesden–Popper Perovskite Light‐Emitting Diodes with Randomly Oriented Nanocrystals. (1st April 2019)

• Record Type: Journal Article
• Authors: Lee, Hyeon‐Dong; Kim, Hobeom; Cho, Himchan; Cha, Wonhee; Hong, Yongseok; Kim, Young‐Hoon; Sadhanala, Aditya; Venugopalan, Vijay; Kim, Joo Sung; Choi, Jin Woo; Lee, Chang‐Lyoul; Kim, Dongho; Yang, Hoichang; Friend, Richard H.; Lee, Tae‐Woo
• Is Part Of: Advanced functional materials. Volume 29:Number 27(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-04-01
• Subjects: carrier transport -- nanocrystal orientation -- nanocrystal pinning -- quasi‐2D perovskite -- structural modulation; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201901225
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Ruddlesden–Popper phase (RP‐phase) perovskites that consist of 2D perovskite slabs interleaved with bulky organic ammonium (OA) are favorable for light‐emitting diodes (LEDs). The critical limitation of LED applications is that the insulating OA arranged in a preferred orientation limits charge transport. Therefore, the ideal solution is to achieve a randomly connected structure that can improve charge transport without hampering the confinement of the electron–hole pair. Here, a structurally modulated RP‐phase metal halide perovskite (MHP), (PEA)2 (CH3 NH3 ) m −1 Pb m Br3 m +1 is introduced to make the randomly oriented RP‐phase unit and ensure good connection between them by applying modified nanocrystal pinning, which leads to an increase in the efficiency of perovskite LEDs (PeLEDs). The randomly connected RP‐phase MHP forces contact between inorganic layers and thereby yields efficient charge transport and radiative recombination. Combined with an optimal dimensionality, (PEA)2 (CH3 NH3 )2 Pb3 Br10, the structurally modulated RP‐phase MHP exhibits increased photoluminescence quantum efficiency, from 0.35% to 30.3%, and their PeLEDs show a 2, 018 times higher current efficiency (20.18 cd A −1 ) than in the 2D PeLED (0.01 cd A −1 ) and 673 times than in the 3D PeLED (0.03 cd A −1 ) using the same film formation process. This approach provides insight on how to solve the limitation of RP‐phase MHP for efficient PeLEDs. Abstract : Ruddlesden–Popper phase (RP‐phase) perovskites are promising materials for optoelectronic devices. Efficient RP‐phase perovskite light‐emitting diodes (PeLEDs) are developed by introducing a structurally modulated RP‐phase metal halide perovskite (MHP) emitter to increase the charge transport ability without hampering the confinement of the electron–hole pair. This approach provides insight on how to solve the limitation of RP‐phase MHP for efficient PeLEDs.