title: Ultrafast Interfacial Electron and Hole Transfer from CsPbBr3 Perovskite Quantum Dots.
abstract: Recently reported colloidal lead halide perovskite quantum dots (QDs) with tunable photoluminescence (PL) wavelengths covering the whole visible spectrum and exceptionally high PL quantum yields (QYs, 50-90%) constitute a new family of functional materials with potential applications in light-harvesting and -emitting devices. By transient absorption spectroscopy, we show that the high PL QYs (∼79%) can be attributed to negligible electron or hole trapping pathways in CsPbBr3 QDs: ∼94% of lowest excitonic states decayed with a single-exponential time constant of 4.5 ± 0.2 ns. Furthermore, excitons in CsPbBr3 QDs can be efficiently dissociated in the presence of electron or hole acceptors. The half-lives of electron transfer (ET) to benzoquinone and subsequent charge recombination are 65 ± 5 ps and 2.6 ± 0.4 ns, respectively. The half-lives for hole transfer (HT) to phenothiazine and the subsequent charge recombination are 49 ± 6 ps and 1.0 ± 0.2 ns, respectively. The lack of electron and hole traps and fast interfacial ET and HT rates are key properties that may enable the development of efficient lead halide perovskite QDs-based light-harvesting and -emitting devices.
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Kaifeng
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.|Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science , Xiangyang, Hubei 441053, China.
authors.forename: Guijie
authors.initials: G
authors.lastname: Liang
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Qiongyi
authors.initials: Q
authors.lastname: Shang
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.|School of Environmental and Civil Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China.
authors.forename: Yueping
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.|College of Electronic Engineering, Heilongjiang University , Harbin, HeilongJiang 150080, China.
authors.forename: Degui
authors.initials: D
authors.lastname: Kong
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Tianquan
authors.initials: T
authors.lastname: Lian