Quantum Dots in Two-Dimensional Perovskite Matrices for Efficient Near-Infrared Light Emission
Fan, James Z.
Sargent, Edward H.
KAUST Grant NumberKUS-11-009-21
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AbstractQuantum-dot-in-perovskite solids are excellent candidates for infrared light-emitting applications. The first generation of dot-in-perovskite light-emitting diodes (LEDs) has shown bright infrared electroluminescence with tunable emission wavelength; however, their performance has been limited by degradation of the active layer at practical operating voltages. This arises from the instability of the three-dimensional (3D) organolead halide perovskite matrix. Herein we report the first dot-in-perovskite solids that employ two-dimensional (2D) perovskites as the matrix. 2D perovskite passivation is achieved via an in situ alkylammonium/alkylamine substitution carried out during the quantum dot (QD) ligand exchange process. This single-step film preparation process enables deposition of the QD/perovskite active layers with thicknesses of 40 nm, over seven times thinner than the first-generation dot-in-perovskite thin films that relied on a multistep synthesis. The dot-in-perovskite film roughness improved from 31 nm for the first-generation films to 3 nm for films as a result of this new approach. The best devices exhibit external quantum efficiency peaks exceeding 2% and radiances of ∼1 W sr–1 m–2, with an improved breakdown voltage up to 7.5 V. Compared to first-generation dot-in-perovskites, this new process reduces materials consumptions 10-fold and represents a promising step toward manufacturable devices.
CitationYang Z, Voznyy O, Walters G, Fan JZ, Liu M, et al. (2017) Quantum Dots in Two-Dimensional Perovskite Matrices for Efficient Near-Infrared Light Emission. ACS Photonics 4: 830–836. Available: http://dx.doi.org/10.1021/acsphotonics.6b00865.
SponsorsThis publication is based in part on work supported by Award KUS-11-009-21, from King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund - Research Excellence Program, and by the Natural Sciences and Engineering Research Council of Canada (NSERC). E. Yassitepe and P. Kanjanaboos are thanked for the assistance of HRTEM, STEM, and AFM measurements. The authors thank L. Gao, R. Wolowiec, D. Kopilovic, and E. Palmiano for their help and useful discussions.
PublisherAmerican Chemical Society (ACS)