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

Autori
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.

Izvornik
Advanced optical materials (2195-1071) 9 (2021), 21; 2100393, 8

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Perovskite Films

Sažetak
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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

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