TY - JOUR
T1 - Enhanced Light Emission Performance of Mixed Cation Perovskite Films—The Effect of Solution Stoichiometry on Crystallization
AU - Liu, Fangzhou
AU - Qin, Xinshun
AU - Han, Bing
AU - Chan, Christopher C.S.
AU - Ma, Chao
AU - Leung, Tik Lun
AU - Chen, Wei
AU - He, Yanling
AU - Lončarić, Ivor
AU - Grisanti, Luca
AU - Ovčar, Juraj
AU - Skoko, Željko
AU - Shi, Yingli
AU - Ling, Francis Chi Chung
AU - Huqe, Md Rashedul
AU - Zapien, Juan Antonio
AU - Wang, Shixun
AU - Su, Chun Jen
AU - Jeng, U. Ser
AU - Wong, Kam Sing
AU - Ng, Alan Man Ching
AU - Gu, Meng
AU - Popović, Jasminka
AU - Djurišić, Aleksandra B.
N1 - Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/11/4
Y1 - 2021/11/4
N2 - 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.
AB - 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.
KW - Ruddlesden–Popper
KW - X-ray diffraction
KW - green emission
KW - perovskite light-emitting diodes
KW - quasi-2D perovskites
UR - https://www.scopus.com/pages/publications/85113168645
U2 - 10.1002/adom.202100393
DO - 10.1002/adom.202100393
M3 - Article
AN - SCOPUS:85113168645
SN - 2195-1071
VL - 9
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 21
M1 - 2100393
ER -