Organic ligands play a pivotal role in lanthanide luminescence by acting as sensitizers for energy absorption and transfer,a phenomenon known as the fluorescence antenna effect.Herein,we introduce two tetradentate nit...Organic ligands play a pivotal role in lanthanide luminescence by acting as sensitizers for energy absorption and transfer,a phenomenon known as the fluorescence antenna effect.Herein,we introduce two tetradentate nitrogen ligands renowned for their efficient sensitization of lanthanide luminescence,with their luminous efficacy finely adjustable through subtle modifications to their structure.Through the synthesis of four Eu(Ⅲ)/Tb(Ⅲ)mono-nuclear complexes via the complexation of ligands 6,6'-bis(4,5-dihydrooxazol-2-yl)-2,2'-bipyridine(bpybox,L^(1))and 6,6'-bis(4,5-dihydrothiazol-2-yl)-2,2'-bipyridine(thio-bpybox,L^(2))with europium/terbium trifluorosulfonate,structural analysis reveals that the lanthanide ion coordinates with eight nitrogen atoms from two ligands and one oxygen atom from trifluorosulfonate.Among them,two Eu(Ⅲ)complexes([Eu(L^(1))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) EuL^(1) and[Eu(L^(2))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) EuL^(2))and one Tb(Ⅲ)complex([Tb(L^(1))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) TbL^(1))exhibit lumi-nosity,displaying characteristic lanthanide metal ion luminescence characterized by high fluorescence quantum yields and prolonged excited state lifetimes.In contrast,TbL^(2)([Tb(L^(2))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2))is non-luminous,with the sole structural distinction being the substitution of oxygen atoms with sulfur atoms within the ligand.This minor alteration significantly impacts the triplet(^(3)T)state energy level of the ligands,thereby influencing their sensitizing effect on Tb(Ⅲ)luminescence.These findings underscore the remarkable efficiency of bpybox-type ligands as sensitizers for Ln(Ⅲ)luminescence,with their structural versatility enabling effective modula-tion of luminous capacities and efficiency.展开更多
The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor （MOS） capacitors with or without ZrAION as the interfacial passivation layer （IPL） are fabricated and their properties are investigated. The experimental r...The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor （MOS） capacitors with or without ZrAION as the interfacial passivation layer （IPL） are fabricated and their properties are investigated. The experimental results show that the GaAs MOS capacitor with the ZrAION IPL exhibits better interracial and electrical properties, including lower interface-state density （1.14 × 10^12 cm^-2eV^-1）, smaller gate leakage current （6.82 × 10^-5 A//cm^2 at Vfb ＋1V）, smaller capacitance equivalent thickness （1.5 nm）, and larger k value （26）. The involved mechanisms lie in the fact that the ZrAION IPL can effectively block the diffusion of Ti and O towards the GaAs surface, thus suppressing the formation of interracial Ga-/As-oxides and As-As dimers, which leads to improved interracial and electrical properties for the devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22371063,22222103,22173015,22025101,and 91961114)the State Key Laboratory of Fine Chemicals at Dalian University of Technology(KF 1607)the Fundamental Research Funds for the Central Universities of China(PA2021GDSK0063,DUT22LAB606).
文摘Organic ligands play a pivotal role in lanthanide luminescence by acting as sensitizers for energy absorption and transfer,a phenomenon known as the fluorescence antenna effect.Herein,we introduce two tetradentate nitrogen ligands renowned for their efficient sensitization of lanthanide luminescence,with their luminous efficacy finely adjustable through subtle modifications to their structure.Through the synthesis of four Eu(Ⅲ)/Tb(Ⅲ)mono-nuclear complexes via the complexation of ligands 6,6'-bis(4,5-dihydrooxazol-2-yl)-2,2'-bipyridine(bpybox,L^(1))and 6,6'-bis(4,5-dihydrothiazol-2-yl)-2,2'-bipyridine(thio-bpybox,L^(2))with europium/terbium trifluorosulfonate,structural analysis reveals that the lanthanide ion coordinates with eight nitrogen atoms from two ligands and one oxygen atom from trifluorosulfonate.Among them,two Eu(Ⅲ)complexes([Eu(L^(1))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) EuL^(1) and[Eu(L^(2))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) EuL^(2))and one Tb(Ⅲ)complex([Tb(L^(1))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2) TbL^(1))exhibit lumi-nosity,displaying characteristic lanthanide metal ion luminescence characterized by high fluorescence quantum yields and prolonged excited state lifetimes.In contrast,TbL^(2)([Tb(L^(2))_(2)(SO_(3)CF_(3))](SO_(3)CF_(3))_(2))is non-luminous,with the sole structural distinction being the substitution of oxygen atoms with sulfur atoms within the ligand.This minor alteration significantly impacts the triplet(^(3)T)state energy level of the ligands,thereby influencing their sensitizing effect on Tb(Ⅲ)luminescence.These findings underscore the remarkable efficiency of bpybox-type ligands as sensitizers for Ln(Ⅲ)luminescence,with their structural versatility enabling effective modula-tion of luminous capacities and efficiency.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61176100,61274112 and 61404055
文摘The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor （MOS） capacitors with or without ZrAION as the interfacial passivation layer （IPL） are fabricated and their properties are investigated. The experimental results show that the GaAs MOS capacitor with the ZrAION IPL exhibits better interracial and electrical properties, including lower interface-state density （1.14 × 10^12 cm^-2eV^-1）, smaller gate leakage current （6.82 × 10^-5 A//cm^2 at Vfb ＋1V）, smaller capacitance equivalent thickness （1.5 nm）, and larger k value （26）. The involved mechanisms lie in the fact that the ZrAION IPL can effectively block the diffusion of Ti and O towards the GaAs surface, thus suppressing the formation of interracial Ga-/As-oxides and As-As dimers, which leads to improved interracial and electrical properties for the devices.
