Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of br...Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of broadband NIR phosphor-converted light emitting diode(pc-LED).However,the purposeful design of a tunable ultra-broadband NIR-emitting phosphor in a single host is still a challenge.In this work,Ga_(2)GeO_(5) with two sites of six-coordinated[Ga1O_(6)]and five-coordinated[Ga2O_(5)]is chosen to host Cr^(3+),successfully producing tunable broadband NIR luminescence(680-1350 nm).It can be tuned largely from 828 to 970 nm with the full-width at half maximum(FWHM)varied from 208 to 258 nm just by simply adjusting the Cr^(3+)-doping content.The tailoring of the Cr^(3+)NIR spectral emission is ascertained to the site occupation preference and competition.The encapsulation of a prototype of NIR pc-LED with an output power of 29.5mW@390 mA is conducted for the implementation of night-vision application.This work provides a novel broadband NIR phosphor by Cr^(3+)-doping in both the sixand five-coordination field,meanwhile,further demonstrating the feasibility of discovering new host material with more than one crystallographic site for Cr^(3+)to trigger tunable broadband NIR emission.展开更多
Fluorescent graphene oxide(GO) nanoparticles were obtained from the thermal carbonization of citrate acid.Depending on the synthesizing temperature,the size of GO varied from several to several hundred nanometers.Owin...Fluorescent graphene oxide(GO) nanoparticles were obtained from the thermal carbonization of citrate acid.Depending on the synthesizing temperature,the size of GO varied from several to several hundred nanometers.Owing to the confinement from the size,green and blue emissions at around 504 and 450 nm were observed from the GO suspension.These emissions could be dynamically quenched by titrating against copper(Ⅱ)(Cu^(2+)) ions,and the emission intensity was reduced exponentially as a function of Cu^(2+)concentration.The quenching mechanism was ascribed to the bridging of the surface-COOH andOH groups by Cu^(2+),which restricted the vibration of edge atoms or clusters and reduced the number of luminophores of GO nanosheets.As a result,the concentration of Cu^(2+)was detectable with the fluorescent intensity of GO.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51802045)Guangzhou basic and applied basic research project (No.202102020871)。
文摘Broadband near-infrared(NIR)light sources play a critical role in widespread applications such as advanced spectroscopy analysis and nondestructive testing.One of the most promising techniques is the fabrication of broadband NIR phosphor-converted light emitting diode(pc-LED).However,the purposeful design of a tunable ultra-broadband NIR-emitting phosphor in a single host is still a challenge.In this work,Ga_(2)GeO_(5) with two sites of six-coordinated[Ga1O_(6)]and five-coordinated[Ga2O_(5)]is chosen to host Cr^(3+),successfully producing tunable broadband NIR luminescence(680-1350 nm).It can be tuned largely from 828 to 970 nm with the full-width at half maximum(FWHM)varied from 208 to 258 nm just by simply adjusting the Cr^(3+)-doping content.The tailoring of the Cr^(3+)NIR spectral emission is ascertained to the site occupation preference and competition.The encapsulation of a prototype of NIR pc-LED with an output power of 29.5mW@390 mA is conducted for the implementation of night-vision application.This work provides a novel broadband NIR phosphor by Cr^(3+)-doping in both the sixand five-coordination field,meanwhile,further demonstrating the feasibility of discovering new host material with more than one crystallographic site for Cr^(3+)to trigger tunable broadband NIR emission.
基金financially supported by One-Hundred Young Talents project from Guangdong University of Technology (No.220413182)。
文摘Fluorescent graphene oxide(GO) nanoparticles were obtained from the thermal carbonization of citrate acid.Depending on the synthesizing temperature,the size of GO varied from several to several hundred nanometers.Owing to the confinement from the size,green and blue emissions at around 504 and 450 nm were observed from the GO suspension.These emissions could be dynamically quenched by titrating against copper(Ⅱ)(Cu^(2+)) ions,and the emission intensity was reduced exponentially as a function of Cu^(2+)concentration.The quenching mechanism was ascribed to the bridging of the surface-COOH andOH groups by Cu^(2+),which restricted the vibration of edge atoms or clusters and reduced the number of luminophores of GO nanosheets.As a result,the concentration of Cu^(2+)was detectable with the fluorescent intensity of GO.
