Rapid Crystallization of All-Inorganic CsPbBr3 Perovskite for High-Brightness Light-Emitting Diodes

Yan Fong Ng; Nur Fadilah Jamaludin; Natalia Yantara; Mingjie Li; Venkata Kameshwar Rao Irukuvarjula; Hilmi Volkan Demir; Tze Chien Sum; Subodh Mhaisalkar; Nripan Mathews

doi:10.1021/acsomega.7b00360

Rapid Crystallization of All-Inorganic CsPbBr₃ Perovskite for High-Brightness Light-Emitting Diodes

ACS Omega. 2017 Jun 19;2(6):2757-2764. doi: 10.1021/acsomega.7b00360. eCollection 2017 Jun 30.

Authors

Yan Fong Ng^{1

2

2}, Nur Fadilah Jamaludin^{1

2

2}, Natalia Yantara¹, Mingjie Li³, Venkata Kameshwar Rao Irukuvarjula¹, Hilmi Volkan Demir^{2

3}, Tze Chien Sum³, Subodh Mhaisalkar^{1

2}, Nripan Mathews^{1

2}

Affiliations

¹ Energy Research Institute @ NTU (ERI@N), Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, 637553 Singapore.
² Interdisciplinary Graduate School, School of Materials Science and Engineering, and LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore.
³ Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore.

Abstract

Research into perovskite-based light-emitting diodes (PeLEDs) has been rapidly gaining momentum since the initial reports of green-emitting methylammonium lead bromide (CH₃NH₃PbBr₃)-based devices were published. However, issues pertaining to its stability and morphological control still hamper progress toward high performing devices. Solvent engineering, a technique typically employed to modulate film crystallization, offers little opportunity for scale-up due to the tendency for inhomogeneous film growth and low degree of reproducibility. Here, we propose and show a simple gas-facilitated process to deposit a stable, all-inorganic perovskite CsPbBr₃ film. The formation of smaller and less percolated grains, which gives rise to enhanced optical properties, highlights the importance of spatial charge confinement in the film. Consequently, the performance of our PeLEDs shows great improvement, with luminance as high as 8218 cd m^-2 and turn-on voltage as low as 2.4 V. Concomitantly, the current efficiency and EQE of our device were increased to 0.72 cd A^-1 and 0.088%, respectively. High reproducibility in the performance of PeLEDs fabricated using this process opens the path for large-area devices.