Halide Homogenization for High-Performance Blue Perovskite Electroluminescence
Open Access
- 1 January 2020
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Research
Abstract
Metal halide perovskite light-emitting diodes (LEDs) have achieved great progress in recent years. However, bright and spectrally stable blue perovskite LED remains a significant challenge. Three-dimensional mixed-halide perovskites have potential to achieve high brightness electroluminescence, but their emission spectra are unstable as a result of halide phase separation. Here, we reveal that there is already heterogeneous distribution of halides in the as-deposited perovskite films, which can trace back to the nonuniform mixture of halides in the precursors. By simply introducing cationic surfactants to improve the homogeneity of the halides in the precursor solution, we can overcome the phase segregation issue and obtain spectrally stable single-phase blue-emitting perovskites. We demonstrate efficient blue perovskite LEDs with high brightness, e.g., luminous efficacy of 4.7, 2.9, and 0.4lmW-1 and luminance of over 37,000, 9,300, and 1,300cdm-2 for sky blue, blue, and deep blue with Commission Internationale de lEclairage (CIE) coordinates of (0.068, 0.268), (0.091, 0.165), and (0.129, 0.061), respectively, suggesting real promise of perovskites for LED applications.Keywords
Funding Information
- Engineering and Physical Sciences Research Council (EP/R025193/1)
- H2020 Marie Sklodowska-Curie Actions (841454)
- Synergetic Innovation Center for Organic Electronics and Information Displays
- Jilin Province Science and Technology Development Program (20190201016JC)
- Natural Science Research of Jiangsu Higher Education Institutions of China (19KJA520004)
- Natural Science Foundation of Jiangsu Province (BK20170991, BK20180085)
- National Science Fund for Distinguished Young Scholars (61725502)
- National Natural Science Foundation of China (61722403, 11674121, 51703094, 61961160733, 61922041, 61875084, 91733302)
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