Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With ...Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With the implementation and emergence of endlessly fascinating UCL features,it is particularly meaningful to understand the photophysical mechanisms inside UCL materials to enable rational subdivision-level structure design,which is however currently far from sufficient.In this work,we take an ordinary upconversion nanoparticle as an example to prove that the UCL decay curves and corresponding lifetimes are indeed a collective response of the entire UCL system to excitations,that exhibits correlated,yet quite different properties from individual ions.A specially developed theoretical random walk model combined with an experimental lifetime control for Yb^(3+)/Er^(3+)UCL demonstrates that ene rgy diffusion principally alters the decay rate.Moreover,the different extent of the influence of energy diffusion on the emissions of ^(2)H_(11/2)/^(4)S_(3/2)(green)and ^(4)F_(9/2)(red)leads to an extremely uncommon crossover comparison of decay rates.This work provides new ideas for understanding decay dynamics and practical UCL lifetime manipulation methods.展开更多
基金Project supported by the National Natural Science Foundation of China(62105235,62205035)the Scientific Research Project of Tianjin Education Commission(2022KJ060)+1 种基金Qinglan Project of Jiangsu Province of ChinaNatural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJD350001)。
文摘Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With the implementation and emergence of endlessly fascinating UCL features,it is particularly meaningful to understand the photophysical mechanisms inside UCL materials to enable rational subdivision-level structure design,which is however currently far from sufficient.In this work,we take an ordinary upconversion nanoparticle as an example to prove that the UCL decay curves and corresponding lifetimes are indeed a collective response of the entire UCL system to excitations,that exhibits correlated,yet quite different properties from individual ions.A specially developed theoretical random walk model combined with an experimental lifetime control for Yb^(3+)/Er^(3+)UCL demonstrates that ene rgy diffusion principally alters the decay rate.Moreover,the different extent of the influence of energy diffusion on the emissions of ^(2)H_(11/2)/^(4)S_(3/2)(green)and ^(4)F_(9/2)(red)leads to an extremely uncommon crossover comparison of decay rates.This work provides new ideas for understanding decay dynamics and practical UCL lifetime manipulation methods.
