title: Brightly Luminescent and Color-Tunable Colloidal CH3NH3PbX3 (X = Br, I, Cl) Quantum Dots: Potential Alternatives for Display Technology.
abstract: Organometal halide perovskites are inexpensive materials with desirable characteristics of color-tunable and narrow-band emissions for lighting and display technology, but they suffer from low photoluminescence quantum yields at low excitation fluencies. Here we developed a ligand-assisted reprecipitation strategy to fabricate brightly luminescent and color-tunable colloidal CH3NH3PbX3 (X = Br, I, Cl) quantum dots with absolute quantum yield up to 70% at room temperature and low excitation fluencies. To illustrate the photoluminescence enhancements in these quantum dots, we conducted comprehensive composition and surface characterizations and determined the time- and temperature-dependent photoluminescence spectra. Comparisons between small-sized CH3NH3PbBr3 quantum dots (average diameter 3.3 nm) and corresponding micrometer-sized bulk particles (2-8 μm) suggest that the intense increased photoluminescence quantum yield originates from the increase of exciton binding energy due to size reduction as well as proper chemical passivations of the Br-rich surface. We further demonstrated wide-color gamut white-light-emitting diodes using green emissive CH3NH3PbBr3 quantum dots and red emissive K2SiF6:Mn(4+) as color converters, providing enhanced color quality for display technology. Moreover, colloidal CH3NH3PbX3 quantum dots are expected to exhibit interesting nanoscale excitonic properties and also have other potential applications in lasers, electroluminescence devices, and optical sensors.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Haizheng
authors.initials: H
authors.lastname: Zhong
authors.affiliation: §Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.forename: Xian-gang
authors.initials: XG
authors.lastname: Wu
authors.affiliation: ‡Micro Nano Technology Center, School of Physics, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian District, Beijing 100081, China.
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Hu
authors.affiliation: ‡Micro Nano Technology Center, School of Physics, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian District, Beijing 100081, China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Huang
authors.affiliation: §Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Junbo
authors.initials: J
authors.lastname: Han
authors.affiliation: ‡Micro Nano Technology Center, School of Physics, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian District, Beijing 100081, China.
authors.forename: Bingsuo
authors.initials: B
authors.lastname: Zou
authors.forename: Yuping
authors.initials: Y
authors.lastname: Dong
keywords: exciton; light-emitting diode; organometal halide perovskites; photoluminescence; quantum dots