The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS）...The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.展开更多
A green long persistent luminescence（LPL） phosphor Ca3Ga4O9：Tb3＋/Zn2＋ was prepared. Ca3 Ga4 O9 matrix exhibits blue self-activated LPL due to the creation of intrinsic traps. When Tb3＋ is doped, the photolumines...A green long persistent luminescence（LPL） phosphor Ca3Ga4O9：Tb3＋/Zn2＋ was prepared. Ca3 Ga4 O9 matrix exhibits blue self-activated LPL due to the creation of intrinsic traps. When Tb3＋ is doped, the photoluminescence（PL） and LPL colors change from blue to green with their intensities significantly enhanced. The doping of Zn^（2＋） evidently improves the PL and LPL performances of the Ca3Ga4O9 matrix and Ca3Ga4O9：Tb^（3＋）. The thermoluminescence（TL） spectra show that a successive trap distribution is formed by multiple intrinsic traps with different depths in the Ca3 Ga4 O9 matrix, and the incorporation of Tb^（3＋） and Zn^（2＋） effectively increases the densities of these intrinsic traps. The existence of a successive trap distribution makes the Ca3 Ga4 O9：Tb^（3＋）/Zn^（2＋） phosphor exhibit thermally stable PL and LPL, It is indicated that this phosphor shows great promise for the application such as high-temperature LPL phosphor.展开更多
We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The additi...We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The addition of Zr^(4+),Ho^(3+)and Er^(3+)can regulate trap distributions and improve energy storage ability of the materials.The LPL perfo rmance of SAO:Mn^(2+),Ho^(3+)is optimal,considering LPL intensity and duration time.Bright LPL of SAO:Mn^(2+),Ho^(3+)can be observed for 3 h by naked eyes in dark after removing the excitation source.Profiles of LPL spectra are different from those of PL,because the two types of Mn^(2+)centers do not play equal parts in LPL and photoluminescence(PL).Trap depths of TL peaks centered at 354 K(peak 1)and 455 K(peak 2)are 0.60 and 0.72 eV,respectively.And peak 1 at 354 K is the effective TL peak responsible for LPL.In SAO:Mn^(2+),Ho^(3+),Mn^(2+)ions doped in Al^(3+)sites serve as emitting centers,and positively charged HoSr defects are the main effective trap centers.Finally,a feasible LPL mechanism of SAO:Mn^(2+),Ho^(3+)was proposed to clarify the generation process of LPL.展开更多
The positive bias temperature instability（PBTI） degradations of high-k/metal gate（HK/MG） n MOSFETs with thin TiN capping layers（1.4 nm and 2.4 nm） are systemically investigated. In this paper, the trap energy di...The positive bias temperature instability（PBTI） degradations of high-k/metal gate（HK/MG） n MOSFETs with thin TiN capping layers（1.4 nm and 2.4 nm） are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI（90℃,125℃, 160℃） are studied and activation energy（Ea） values（0.13 eV and 0.15 eV） are extracted. Although the equivalent oxide thickness（EOT） values of two TiN thickness values are almost similar（0.85 nm and 0.87 nm）, the 2.4-nm TiN one（thicker Ti N capping layer） shows better PBTI reliability（13.41% at 0.9 V, 90℃, 1000 s）. This is due to the better interfacial layer/high-k（IL/HK） interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer.展开更多
A new modified method based on the charge pumping technique is proposed and adopted to extract the lateral profiles of oxide charges in an advanced MOSFET. A 0.12 μm SONOS device with 50 nm threshold voltage peak is ...A new modified method based on the charge pumping technique is proposed and adopted to extract the lateral profiles of oxide charges in an advanced MOSFET. A 0.12 μm SONOS device with 50 nm threshold voltage peak is designed and utilized to demonstrate the proposed method. The trapped charge distribution with a narrow peak can be precisely characterized with this method, which shows good consistency with the measured threshold voltage.展开更多
In this paper,the effect of gamma-ray irradiation on the electrical conductivity of polypropylene(PP)composites has been studied.The samples are prepared using PP and styrene-ethylene-butylene-styrene elastomer with c...In this paper,the effect of gamma-ray irradiation on the electrical conductivity of polypropylene(PP)composites has been studied.The samples are prepared using PP and styrene-ethylene-butylene-styrene elastomer with contents ranging from 0 wt%to 50 wt%,and exposed to Cobalt-60 gamma irradiation,with a dose from 0 to 250 kGy.Electrical conductivities at different temperatures and trap distributions are measured to observe the deterioration of insulation performance.The microstructure of the sample is estimated using differential scanning calorimetry,X-ray diffraction,thermogravimetric analysis and a scanning electron microscope.The obtained results demonstrate a correlation between the increase in electrical conductivity and the elevation in both total dose and temperature.At 250 kGy,the trap distribution tends to become shallower,accompanied by a decrease in crystallinity,melting and decomposition temperatures of the sample.The PP composite exhibits better stability against irradiation and thermal effects,primarily due to the cross-linked structures formed by irradiation.展开更多
Aerospace dielectric components on spacecrafts are frequently exposed to surface charging.Here the dynamic charging behaviours of advanced aerospace dielectrics under electron beam irradiation are investigated.Combine...Aerospace dielectric components on spacecrafts are frequently exposed to surface charging.Here the dynamic charging behaviours of advanced aerospace dielectrics under electron beam irradiation are investigated.Combined measurement of dielectric secondary emission yield(SEY)and trap distribution provides input parameters of a driftdiffusion transport model reproducing the beam-irradiated dielectric charging processes.The model reveals the spatial-temporal evolutions of the current,charge density,and electric field distribution.The model-predicted sample current,SEY and surface potential,in a surface layer of 1μm and with incident electron energy range of 10-30 keV,are compared with the experiments,showing qualitative agreement.The effects of beam energy and current,dielectric material,and sample thickness on the charging processes are explored.Relation between the beam energy and final surface potential is determined,and the beam current is found to only affect the charging speed.Dielectric parameters including the mass density,permittivity,surface resistivity,trap state distribution,electron affinity,together influence the charging speed and final charged state.展开更多
A physical drain current model of polysilicon thin-film transistors based on the charge-sheet model, the density of trap states and surface potential is proposed.The model uses non-iterative calculations,which are sin...A physical drain current model of polysilicon thin-film transistors based on the charge-sheet model, the density of trap states and surface potential is proposed.The model uses non-iterative calculations,which are single-piece and valid in all operation regions above flat-band voltage.The distribution of the trap states,including both Gaussian deep-level states and exponential band-tail states,is also taken into account,and parameter extraction of trap state distribution is developed by the optoelectronic modulation spectroscopy measurement method. Comparisons with the available experimental data are accomplished,and good agreements are obtained.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 51337002,51077028,51502063 and 51307046the Foundation of Harbin Science and Technology Bureau of Heilongjiang Province under Grant No RC2014QN017034
文摘The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.
基金supported by the National Natural Science Foundation of China(11774138)the Society Development Foundation of Yunnan Province(2016FA021)the Kunming University of Science and Technology(KKSY201632046)
文摘A green long persistent luminescence（LPL） phosphor Ca3Ga4O9：Tb3＋/Zn2＋ was prepared. Ca3 Ga4 O9 matrix exhibits blue self-activated LPL due to the creation of intrinsic traps. When Tb3＋ is doped, the photoluminescence（PL） and LPL colors change from blue to green with their intensities significantly enhanced. The doping of Zn^（2＋） evidently improves the PL and LPL performances of the Ca3Ga4O9 matrix and Ca3Ga4O9：Tb^（3＋）. The thermoluminescence（TL） spectra show that a successive trap distribution is formed by multiple intrinsic traps with different depths in the Ca3 Ga4 O9 matrix, and the incorporation of Tb^（3＋） and Zn^（2＋） effectively increases the densities of these intrinsic traps. The existence of a successive trap distribution makes the Ca3 Ga4 O9：Tb^（3＋）/Zn^（2＋） phosphor exhibit thermally stable PL and LPL, It is indicated that this phosphor shows great promise for the application such as high-temperature LPL phosphor.
基金Project supported by the National Natural Science Foundation of China(51802137)the Natural Science Foundation of Shandong Province of China(ZR2019BEM010)+1 种基金the State Key Research Projects of Shandong Natural Science Foundation(ZR2020KB019)Yantai High End Talent Introduction"Double Hundred Plan"Special Fund,the Research Fund of Ludong University(ZR2021004)。
文摘We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The addition of Zr^(4+),Ho^(3+)and Er^(3+)can regulate trap distributions and improve energy storage ability of the materials.The LPL perfo rmance of SAO:Mn^(2+),Ho^(3+)is optimal,considering LPL intensity and duration time.Bright LPL of SAO:Mn^(2+),Ho^(3+)can be observed for 3 h by naked eyes in dark after removing the excitation source.Profiles of LPL spectra are different from those of PL,because the two types of Mn^(2+)centers do not play equal parts in LPL and photoluminescence(PL).Trap depths of TL peaks centered at 354 K(peak 1)and 455 K(peak 2)are 0.60 and 0.72 eV,respectively.And peak 1 at 354 K is the effective TL peak responsible for LPL.In SAO:Mn^(2+),Ho^(3+),Mn^(2+)ions doped in Al^(3+)sites serve as emitting centers,and positively charged HoSr defects are the main effective trap centers.Finally,a feasible LPL mechanism of SAO:Mn^(2+),Ho^(3+)was proposed to clarify the generation process of LPL.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.SS2015AA010601)the National Natural Science Foundation of China(Grant Nos.61176091 and 61306129)
文摘The positive bias temperature instability（PBTI） degradations of high-k/metal gate（HK/MG） n MOSFETs with thin TiN capping layers（1.4 nm and 2.4 nm） are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI（90℃,125℃, 160℃） are studied and activation energy（Ea） values（0.13 eV and 0.15 eV） are extracted. Although the equivalent oxide thickness（EOT） values of two TiN thickness values are almost similar（0.85 nm and 0.87 nm）, the 2.4-nm TiN one（thicker Ti N capping layer） shows better PBTI reliability（13.41% at 0.9 V, 90℃, 1000 s）. This is due to the better interfacial layer/high-k（IL/HK） interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer.
基金Project supported by the National Basic Research Program of China(No.2006CB302700)the National Natural Science Foundation of China(No.60876076)the National Key Scientific and Technological Project of China(No.2009ZX02023-5-3)
文摘A new modified method based on the charge pumping technique is proposed and adopted to extract the lateral profiles of oxide charges in an advanced MOSFET. A 0.12 μm SONOS device with 50 nm threshold voltage peak is designed and utilized to demonstrate the proposed method. The trapped charge distribution with a narrow peak can be precisely characterized with this method, which shows good consistency with the measured threshold voltage.
基金National Natural Science Foundation of China,Grant/Award Number:NSFC52077151State Key Laboratory of Electrical Insulation and Power Equipment,Grant/Award Number:EIPE23208Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education,Grant/Award Number:KFM202203。
文摘In this paper,the effect of gamma-ray irradiation on the electrical conductivity of polypropylene(PP)composites has been studied.The samples are prepared using PP and styrene-ethylene-butylene-styrene elastomer with contents ranging from 0 wt%to 50 wt%,and exposed to Cobalt-60 gamma irradiation,with a dose from 0 to 250 kGy.Electrical conductivities at different temperatures and trap distributions are measured to observe the deterioration of insulation performance.The microstructure of the sample is estimated using differential scanning calorimetry,X-ray diffraction,thermogravimetric analysis and a scanning electron microscope.The obtained results demonstrate a correlation between the increase in electrical conductivity and the elevation in both total dose and temperature.At 250 kGy,the trap distribution tends to become shallower,accompanied by a decrease in crystallinity,melting and decomposition temperatures of the sample.The PP composite exhibits better stability against irradiation and thermal effects,primarily due to the cross-linked structures formed by irradiation.
基金National Natural Science Foundation of China,Grant/Award Number:12375205Fundamental Research Funds for the Central Universities,Grant/Award Number:xzy012023153Swiss National Science Foundation。
文摘Aerospace dielectric components on spacecrafts are frequently exposed to surface charging.Here the dynamic charging behaviours of advanced aerospace dielectrics under electron beam irradiation are investigated.Combined measurement of dielectric secondary emission yield(SEY)and trap distribution provides input parameters of a driftdiffusion transport model reproducing the beam-irradiated dielectric charging processes.The model reveals the spatial-temporal evolutions of the current,charge density,and electric field distribution.The model-predicted sample current,SEY and surface potential,in a surface layer of 1μm and with incident electron energy range of 10-30 keV,are compared with the experiments,showing qualitative agreement.The effects of beam energy and current,dielectric material,and sample thickness on the charging processes are explored.Relation between the beam energy and final surface potential is determined,and the beam current is found to only affect the charging speed.Dielectric parameters including the mass density,permittivity,surface resistivity,trap state distribution,electron affinity,together influence the charging speed and final charged state.
基金Project supported by the Key Project of Chinese Ministry of Education(No.211206)the Fundamental Research Funds for the Central Universities (No.21611422)the Foundation for Distinguished Young Talents in Higher Education of Guangdong,China(No.LYM10032)
文摘A physical drain current model of polysilicon thin-film transistors based on the charge-sheet model, the density of trap states and surface potential is proposed.The model uses non-iterative calculations,which are single-piece and valid in all operation regions above flat-band voltage.The distribution of the trap states,including both Gaussian deep-level states and exponential band-tail states,is also taken into account,and parameter extraction of trap state distribution is developed by the optoelectronic modulation spectroscopy measurement method. Comparisons with the available experimental data are accomplished,and good agreements are obtained.
