title: Nonlinear spectral and lifetime management in upconversion nanoparticles by controlling energy distribution.
abstract: Optical tuning of lanthanide-doped upconversion nanoparticles has attracted considerable attention over the past decade because this development allows the advance of new frontiers in energy conversion, materials science, and biological imaging. Here we present a rational approach to manipulating the spectral profile and lifetime of lanthanide emission in upconversion nanoparticles by tailoring their nonlinear optical properties. We demonstrate that the incorporation of energy distributors, such as surface defects or an extra amount of dopants, into a rare-earth-based host lattice alters the decay behavior of excited sensitizers, thus markedly improving the emitters' sensitivity to excitation power. This work provides insight into mechanistic understanding of upconversion phenomena in nanoparticles and also enables exciting new opportunities of using these nanomaterials for photonic applications.
authors.affiliation: Department of Chemistry, National University of Singapore, Singapore 117543, Singapore. chmlx@nus.edu.sg.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemistry, National University of Singapore, Singapore 117543, Singapore. chmlx@nus.edu.sg.
authors.forename: Renren
authors.initials: R
authors.lastname: Deng
authors.affiliation: Key Laboratory of Flexible Electronics, Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China. iamlhuang@njtech.edu.cn.
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Xie
authors.affiliation: Key Laboratory of Flexible Electronics, Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China. iamlhuang@njtech.edu.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Chemistry, National University of Singapore, Singapore 117543, Singapore. chmlx@nus.edu.sg and Center for Functional Materials, NUS (Suzhou) Research Institute, Suzhou, Jiangsu 215123, China and SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Liu