Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are cr...Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.展开更多
High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic targe...High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.展开更多
This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al...This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al films with good adherence to the substrates having a (002) preferred orientation have been obtained with resistivities in the range from 4.1×10-3to 5.3×104 Ωcm, carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2/V/s for films. The average transmittance reaches 75% in the visible spectrum. The quality of obtained films depends on substrate temperature during film fabrication.展开更多
Aqueous Zn-ion battery has emerged as one of the most prospective energy storage devices due to its low cost,high safety,and eco-friendliness.However,Zn-ion batteries are bottlenecked by significant capacity fading du...Aqueous Zn-ion battery has emerged as one of the most prospective energy storage devices due to its low cost,high safety,and eco-friendliness.However,Zn-ion batteries are bottlenecked by significant capacity fading during long-term cycling and poor performance at high current rates.Here,we report an available cooperation of multivariate manganese oxides@carbon hybrids(MnO_(2)/MnO@C and MnO_(2)/Mn_(3)O_(4)@C)via a plasma-assisted design as an attractive Zn-ion cathode.Among them,the MnO_(2)/MnO@C cathode exhibits a reversible specific capacity of 165 m Ah g^(-1)over 200 cycles at a high rate of 0.5 A g^(-1),and possesses great rate performance with high capacities of 110 and 100 m Ah g^(-1)at a high rate of 0.8 and 1 A g^(-1),respectively.The good cathode performance significantly results from the facile charge transfer and ions(Zn^(2+)and H^(+))insertion in the manganese oxides/carbon hybrids featuring phase stability behavior in the available cooperation of multivalence and carbon conductive substrates.This work will promote the Zn-manganese dioxide system for the design of low-cost and high-performance aqueous rechargeable Zn-ion batteries.展开更多
Understanding the substrate and temperature effect on thermal transport properties of transition metal dichalcogenides(TMDs)monolayers are crucial for their future applications.Herein,a dual-wavelength flash Raman(DF-...Understanding the substrate and temperature effect on thermal transport properties of transition metal dichalcogenides(TMDs)monolayers are crucial for their future applications.Herein,a dual-wavelength flash Raman(DF-Raman)method is used to measure the thermal conductivity of monolayer WS_(2) at a temperature range of 200–400 K.High measurement accuracy can be guaranteed in this method since the influence of both the laser absorption coefficient and temperature-Raman coefficient can be eliminated through normalization.The room-temperature thermal conductivity of suspended and supported WS_(2) are 28.5±2.1(30.3±2.0)and 15.4±1.9(16.9±2.1)W/(m·K),respectively,with a~50%reduction due to substrate effect.Molecular dynamics(MD)simulations reveal that the suppression of acoustic phonons is mainly responsible for the striking reduction.The behaviors of optical phonons are also unambiguously investigated using Raman spectroscopy,and the in-plane optical mode,E(Γ),is surprisingly found to be slightly enhanced while out-of-plane mode,A1g(Γ),is suppressed due to substrate interaction,mutually verified with MD results.Our study provides a solid understanding of the phonon transport behavior of WS_(2) with substrate interaction,which provides guidance for TMDs-based nanodevices.展开更多
The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized w...The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized with X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, transmittance spectroscopy and specific heat measurement. Results revealed that with proper Nd doped, Nd^（3＋） ions solid dissolved in Al_2O_3 lattice, resulting in small and uniform grain and high bonding vibration, which was beneficial to transparent and thermal properties. With 1000 ppm Nd doped, Al_2O_3 translucent ceramics showed a total transmittance of 89% and thermal conductivity of 41.7 W/m/K, indicating a potential application as substrate for effective heat dissipation and multi emitting surface in LEDs module.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11374114
文摘Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University, Ministry of Education, China (No.IRT0547)
文摘High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.
基金This work is supported by the National Natural Srience Foundation of China(No.69876025 and No.60076006)Science and Technology Committee of Shandong Province and the Natural Science Foundation of Shandong Province.
文摘This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al films with good adherence to the substrates having a (002) preferred orientation have been obtained with resistivities in the range from 4.1×10-3to 5.3×104 Ωcm, carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2/V/s for films. The average transmittance reaches 75% in the visible spectrum. The quality of obtained films depends on substrate temperature during film fabrication.
基金supported by the National Natural Science Foundation of China(Nos.51822104,52071144,51831009,and 11575126)the Guangzhou Science and Technology Plan Projects(No.201904020018)the Fundamental Research Funds for the Central Universities,SCUT(No.2019CG24)
文摘Aqueous Zn-ion battery has emerged as one of the most prospective energy storage devices due to its low cost,high safety,and eco-friendliness.However,Zn-ion batteries are bottlenecked by significant capacity fading during long-term cycling and poor performance at high current rates.Here,we report an available cooperation of multivariate manganese oxides@carbon hybrids(MnO_(2)/MnO@C and MnO_(2)/Mn_(3)O_(4)@C)via a plasma-assisted design as an attractive Zn-ion cathode.Among them,the MnO_(2)/MnO@C cathode exhibits a reversible specific capacity of 165 m Ah g^(-1)over 200 cycles at a high rate of 0.5 A g^(-1),and possesses great rate performance with high capacities of 110 and 100 m Ah g^(-1)at a high rate of 0.8 and 1 A g^(-1),respectively.The good cathode performance significantly results from the facile charge transfer and ions(Zn^(2+)and H^(+))insertion in the manganese oxides/carbon hybrids featuring phase stability behavior in the available cooperation of multivalence and carbon conductive substrates.This work will promote the Zn-manganese dioxide system for the design of low-cost and high-performance aqueous rechargeable Zn-ion batteries.
基金supported by the National Natural Science Foundation of China(Nos.51827807,51972191,and 52130602).
文摘Understanding the substrate and temperature effect on thermal transport properties of transition metal dichalcogenides(TMDs)monolayers are crucial for their future applications.Herein,a dual-wavelength flash Raman(DF-Raman)method is used to measure the thermal conductivity of monolayer WS_(2) at a temperature range of 200–400 K.High measurement accuracy can be guaranteed in this method since the influence of both the laser absorption coefficient and temperature-Raman coefficient can be eliminated through normalization.The room-temperature thermal conductivity of suspended and supported WS_(2) are 28.5±2.1(30.3±2.0)and 15.4±1.9(16.9±2.1)W/(m·K),respectively,with a~50%reduction due to substrate effect.Molecular dynamics(MD)simulations reveal that the suppression of acoustic phonons is mainly responsible for the striking reduction.The behaviors of optical phonons are also unambiguously investigated using Raman spectroscopy,and the in-plane optical mode,E(Γ),is surprisingly found to be slightly enhanced while out-of-plane mode,A1g(Γ),is suppressed due to substrate interaction,mutually verified with MD results.Our study provides a solid understanding of the phonon transport behavior of WS_(2) with substrate interaction,which provides guidance for TMDs-based nanodevices.
基金financially supported by the National Key R&D Program of China (2021YFA1500800)the National Natural Science Foundation of China (51825204, 52072377, and 52188101)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2020192)the Natural Science Foundation of Liaoning Province (2021MS-014)the financial support from the New Cornerstone Science Foundation through the XPLORER PRIZE
基金supported by the project of Natural Science Foundation of Zhejiang Province(LY15F050005 and LZ14B010001)
文摘The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized with X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, transmittance spectroscopy and specific heat measurement. Results revealed that with proper Nd doped, Nd^（3＋） ions solid dissolved in Al_2O_3 lattice, resulting in small and uniform grain and high bonding vibration, which was beneficial to transparent and thermal properties. With 1000 ppm Nd doped, Al_2O_3 translucent ceramics showed a total transmittance of 89% and thermal conductivity of 41.7 W/m/K, indicating a potential application as substrate for effective heat dissipation and multi emitting surface in LEDs module.
