Phototherapeutic applications gain more and more interests and require fundamental progresses in interdisciplinarity research,particularly a novel topical phototherapy using ultraviolet-B(UVB,~310 nm)upconverting phos...Phototherapeutic applications gain more and more interests and require fundamental progresses in interdisciplinarity research,particularly a novel topical phototherapy using ultraviolet-B(UVB,~310 nm)upconverting phosphors.In this study,three synthesis methods with(out)sintering processes were implemented to obtain micro-/nano-size Y_(2)O_(3):RE^(3+)/Gd^(3+)(RE=Er,Ho)particles using RE oxides(RE_(2)O_(3)),RE-nitrates(RE(NO_(3))_(3))and RE-chlorides(RECl_(3))as starting materials.Pumped by an OPO laser at wavelengths of 450 and/or 490 nm,blue-to-UVB upconversion with narrowband peak at 313 nm was effectively realized for all the Y_(2)O_(3):RE^(3+)/Gd^(3+)powder phosphors.On basis of theoretical speculations and experimental data,a two-photon absorption process was proposed for the UVB upconversion of Y_(2)O_(3):RE^(3+)/Gd^(3+).Moreover,the involved energy transfer(ET)from RE^(3+)to Gd^(3+),its back ET mechanisms as well as cross-relaxation between RE^(3+)(RE=Er,Ho)ions were systematically treated versus the Er^(3+)-or Ho^(3+)-,and Gd^(3+)-doping concentration.Note that the UVB upconversion intensity will decline severely as the particles become smaller to submicron and nanoscale,likely due to an increasing surface-tovolume ratio along with more surface defects appearance.All these results would greatly promote the development of novel blue-to-UVB upconverting materials,and their potential applications in topical phototherapy irradiated by blue light source.展开更多
基金Project supported by the National Natural Science Foundation of China(62475155)the Nederlandse Organisatie voor Wetenschappelijk Onderzoek(731.017.302)the Shanghai Natural Science Foundation(23ZR1445000)。
文摘Phototherapeutic applications gain more and more interests and require fundamental progresses in interdisciplinarity research,particularly a novel topical phototherapy using ultraviolet-B(UVB,~310 nm)upconverting phosphors.In this study,three synthesis methods with(out)sintering processes were implemented to obtain micro-/nano-size Y_(2)O_(3):RE^(3+)/Gd^(3+)(RE=Er,Ho)particles using RE oxides(RE_(2)O_(3)),RE-nitrates(RE(NO_(3))_(3))and RE-chlorides(RECl_(3))as starting materials.Pumped by an OPO laser at wavelengths of 450 and/or 490 nm,blue-to-UVB upconversion with narrowband peak at 313 nm was effectively realized for all the Y_(2)O_(3):RE^(3+)/Gd^(3+)powder phosphors.On basis of theoretical speculations and experimental data,a two-photon absorption process was proposed for the UVB upconversion of Y_(2)O_(3):RE^(3+)/Gd^(3+).Moreover,the involved energy transfer(ET)from RE^(3+)to Gd^(3+),its back ET mechanisms as well as cross-relaxation between RE^(3+)(RE=Er,Ho)ions were systematically treated versus the Er^(3+)-or Ho^(3+)-,and Gd^(3+)-doping concentration.Note that the UVB upconversion intensity will decline severely as the particles become smaller to submicron and nanoscale,likely due to an increasing surface-tovolume ratio along with more surface defects appearance.All these results would greatly promote the development of novel blue-to-UVB upconverting materials,and their potential applications in topical phototherapy irradiated by blue light source.
