Colloidal cesium lead bromide-based anisotropic nanorods for improving outcoupling in perovskite light-emitting diodes

ABSTRACT

Photon extraction is one of the major issues limiting outcoupling efficiency in perovskite light-emitting diodes (PeLEDs). Light outcoupling in PeLEDs is typically limited by the disparity in refractive indices among the consisting layers and the difficulty of producing directed emitters in the emitting layers. Here, anisotropic nanorod-based perovskite with colloidal cesium lead bromide was introduced to address the issue via the oil–water interface chemical stripping transition method. It was confirmed that the horizontal transition dipole moments of 73% and refractive index value of 1.86 of the ANRs-based perovskites enhance outcoupling efficiency in PeLEDs. Finally, we achieved green-emitting ANR-PeLEDs with a current efficiency of 45.9 cd/A, power efficiency of 40.0 lm/W, and external quantum efficiency of 18.4% (turn-on voltage 3.3 V), with Commission Internationale de l'Eclairage (CIE) coordinates of (0.073, 0.71). These findings suggest further research into the anisotropic 1D shape of perovskite, which could improve the optoelectrical performance of PeLEDs.

KEYWORDS:

• Anisotropic nanorods
• internal light-confinement
• in-plane transition dipole moments
• refractive indices matching
• outcoupling efficiency

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education [grant number 2022R1A6A1A03051705], and by Korea Basic Science Institute (National Research Facilities and Equipment Center), with a grant funded by the Ministry of Education [grant number 2022R1A6C101B762. In addition, this work was supported by the Ministry of Science, ICT & Future Planning, and Technology Innovation Program [grant number 20014528], funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea). This work was also supported by Korea Institute for Advancement of Technology (KIAT), with a grant funded by the Korean Government (MOTIE) [grant number P0008458, HRD Program for Industrial Innovation].

Notes on contributors

Muhammad Imran Saleem

Muhammad Imran Saleem received his PhD degree from the School of Physics Beijing Institute of Technology, China. Since 2022, he has been working as a postdoctoral researcher at the Department of Materials Science and Engineering at Inha University, Incheon, South Korea. His research focuses on perovskite optoelectronic devices.

Jeong-Hwan Lee

Jeong-Hwan Lee received his PhD from the Department of Materials Science and Engineering at Seoul National University under the supervision of Prof. Jang-Joo Kim in 2014. During 2014–2017, he carried out his postdoctoral work in Imec, Belgium. Then, he joined the faculty at Inha University in 2017. His research interests have centered on organic semiconductors for electronics and photonics, which are regarded as new materials for information processing. His current research topics include electroluminescence and sensing by using various material systems from organic to organic/inorganic hybrid materials. In electroluminescence, the fundamental physics of materials and EL devices, degradation mechanism, new device structures to improve EL efficiency, and novel devices such as lasers are investigated.