Tuning Phonon Energies in Lanthanide-doped Potassium Lead Halide Nanocrystals for Enhanced Nonlinearity and Upconversion |
| |
Authors: | Dr Zhuolei Zhang Dr Artiom Skripka Dr Jakob C Dahl Dr Chaochao Dun Dr Jeffrey J Urban Dr Daniel Jaque Dr P James Schuck Dr Bruce E Cohen Dr Emory M Chan |
| |
Institution: | 1. School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Load, Wuhan, 430074 China;2. The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA;3. Nanomaterials for Bioimaging Group (nanoBIG), Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain;4. Department of Mechanical Engineering, Columbia University, New York, NY 10027 USA |
| |
Abstract: | Optical applications of lanthanide-doped nanoparticles require materials with low phonon energies to minimize nonradiative relaxation and promote nonlinear processes like upconversion. Heavy halide hosts offer low phonon energies but are challenging to synthesize as nanocrystals. Here, we demonstrate the size-controlled synthesis of low-phonon-energy KPb2X5 (X=Cl, Br) nanoparticles and the ability to tune nanocrystal phonon energies as low as 128 cm−1. KPb2Cl5 nanoparticles are moisture resistant and can be efficiently doped with lighter lanthanides. The low phonon energies of KPb2X5 nanoparticles promote upconversion luminescence from higher lanthanide excited states and enable highly nonlinear, avalanche-like emission from KPb2Cl5 : Nd3+ nanoparticles. The realization of nanoparticles with tunable, ultra-low phonon energies facilitates the discovery of nanomaterials with phonon-dependent properties, precisely engineered for applications in nanoscale imaging, sensing, luminescence thermometry and energy conversion. |
| |
Keywords: | KPb2Cl5 Nanoparticles Perovskite Phonon Engineering Photon Avalanche Upconversion |
|
|