Enhanced Light Emission Performance of Mixed Cation Perovskite Films—The Effect of Solution Stoichiometry on Crystallization

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Fangzhou Liu
  • Xinshun Qin
  • Bing Han
  • Christopher C. S. Chan
  • Chao Ma
  • Tik Lun Leung
  • Wei Chen
  • Yanling He
  • Ivor Lončarić
  • Luca Grisanti
  • Juraj Ovčar
  • Željko Skoko
  • Yingli Shi
  • Francis Chi Chung Ling
  • Chun-Jen Su
  • U-Ser Jeng
  • Kam Sing Wong
  • Alan Man Ching Ng
  • Meng Gu
  • Jasminka Popović
  • Aleksandra B. Djurišić

Detail(s)

Original languageEnglish
Article number2100393
Journal / PublicationAdvanced Optical Materials
Volume9
Issue number21
Online published20 Aug 2021
Publication statusPublished - 4 Nov 2021

Abstract

The performance of quasi-2D perovskite light emitting diodes (LEDs) with mixed small cations, cesium and formamidinium (FA), is significantly affected by their ratio. The best devices obtained for Cs:FA ratio of 1:1 exhibit a maximum external quantum efficiency (EQE) of 12.1%, maximum luminance of 15 070 cd m−2 and maximum current efficiency of 46.1 cd A−1, which is significantly higher (about 3 times) compared to devices with FA only (maximum EQE of 4.1%, maximum luminance of 4521 cd m−2) and Cs-only (maximum EQE of 4.0%, maximum luminance of 4886 cd m−2). The photoluminescence quantum yield of the Cs:FA 1:1 sample is similarly enhanced, 21.3% compared 5.4% and 6%, for FA-only and Cs-only samples, respectively. It can be observed that the Cs:FA ratio significantly affects the crystallization of the perovskite, with the optimal 1:1 ratio resulting in the formation of tetragonal Cs0.5FA0.5PbBr3 phase (different from cubic FAPbBr3 and orthorhombic CsPbBr3) with pronounced preferential orientation as well as a significant reduction in the trap density, which leads to a substantial improvement in the light-emitting performance.

Research Area(s)

  • green emission, perovskite light-emitting diodes, quasi-2D perovskites, Ruddlesden–Popper, X-ray diffraction

Citation Format(s)

Enhanced Light Emission Performance of Mixed Cation Perovskite Films—The Effect of Solution Stoichiometry on Crystallization. / Liu, Fangzhou; Qin, Xinshun; Han, Bing; Chan, Christopher C. S.; Ma, Chao; Leung, Tik Lun; Chen, Wei; He, Yanling; Lončarić, Ivor; Grisanti, Luca; Ovčar, Juraj; Skoko, Željko; Shi, Yingli; Ling, Francis Chi Chung; Huqe, Md Rashedul; Zapien, Juan Antonio; Wang, Shixun; Su, Chun-Jen; Jeng, U-Ser; Wong, Kam Sing; Ng, Alan Man Ching; Gu, Meng; Popović, Jasminka; Djurišić, Aleksandra B.

In: Advanced Optical Materials, Vol. 9, No. 21, 2100393, 04.11.2021.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review