GeTe-based alloys are promising thermoelectric materials for use at medium temperatures owing to their excellent thermoelectric performance.In this study,Ge_(0.8-x)Mn_(0.1)Pb_(0.1)Sb_(x)Te alloys were obtained via vac...GeTe-based alloys are promising thermoelectric materials for use at medium temperatures owing to their excellent thermoelectric performance.In this study,Ge_(0.8-x)Mn_(0.1)Pb_(0.1)Sb_(x)Te alloys were obtained via vacuum melting and hot-press sintering.Sb doping effectively decreased the carrier concentration,resulting in an enhancement of the Seebeck coefficient and consequently imparting excellent electrical transport performance to the sample.With doping concentration increasing,the structure of the sample changed from rhombohedral to cubic,creating a more favorable band structure for electronic transport properties.The incorporation of Sb into GeTe intensifies the lattice defects within the material.The significant decrease in the lattice thermal conductivity of the Ge_(0.71)Mn_(0.1)Pb_(0.1)Sb_(0.09)Te alloy to 0.84 W m^(-1)K^(-1)at 323 K is primarily attributed to the phonon scattering effect emanating from the presence of edge dislocation,point defects,and inherent grain boundaries.Finally,the maximum ZT value of the Ge_(0.74)Mn_(0.1)Pb_(0.1)Sb_(0.06)Te alloy was~1.53773 K,which is a significant enhancement of 0.35 compared to the undoped Ge_(0.8)Mn_(0.1)Pb_(0.1)Te alloy.This substantial improvement underscores the positive impact of the selected doping elements and their concentrations on the overall thermoelectric performance of the alloy.展开更多
Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by dire...Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by direct Sb doping method.It can be found that doping Sb into Bi_(2)Te_(3) lattice array for Bi-site replacement facilitates the generation of Sb′Te anti-site defects.This anti-site defects can increase the hole concentration and optimize electrical transport properties of Bi_(2−x)Sb_(x)Te_(3) alloys.In addition,the point defects induced by mass and stress fluctuations and the Sb impurities produced during the sintering process can enhance the multi-scale phonon scattering and reduce the lattice thermal conductivity.As a result,the Bi_(0.47)Sb_(1.63)Te_(3) sample has a maximum thermoelectric figure of merit ZT of 1.04 at 350 K.It is worth noting that the bipolar effect of Bi_(2)Te_(3)-based alloys can be weakened with the increase of Sb content.The Bi_(0.44)Sb_(1.66)Te_(3) sample has a maximum average ZT value(0.93)in the temperature range of 300–500 K,indicating that direct doping of Sb can broaden the temperature range corresponding to the optimal ZT value.This work provides an idea for developing high-performance near room temperature thermoelectric materials with a wide temperature range.展开更多
Chrysanthemum-like ZnO nanowire clusters with different Sb-doping concentrations were prepared using a hy- drothermal process. The microstructures, morphologies, and dielectric properties of the as-prepared products w...Chrysanthemum-like ZnO nanowire clusters with different Sb-doping concentrations were prepared using a hy- drothermal process. The microstructures, morphologies, and dielectric properties of the as-prepared products were characterized by X-ray diffraction （XRD）, high-resolution transmission electron microscopy （HRTEM）, field emission environment scanning electron microscope （FEESEM）, and microwave vector network analyzer respectively. The results indicate that the as-prepared products are Sb-doped ZnO single crystallines with a hexagonal wurtzite structure, the flower bud saturation degree Fd is obviously different from that of the pure ZnO nanowire clusters, the good dielectric loss property is found in Sb-doped ZnO products with low density, and the dielectric loss tangent tanSe increases with the increase of the Sb-doping concentration in a certain concentration range.展开更多
GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to th...GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to that of their bulk counterparts have not yet been reported,because of their unsatisfactory electrical and thermal properties caused by their poor crystal quality and high carrier concentration.Herein,a series of Sb-doped GeTe films and devices with remarkable thermoelectric performances are presented.These films are prepared through magnetron sputtering deposition at 553 K and exhibit a unique microstructure that consists of coarse-and fine-sized grains with high crystallization quality.The fine grains enhance the scattering associated with phonon transport and the coarse grains provide electron transport channels,which can suppress the thermal conductivity without obviously sacrificing the electrical conductivity.Moreover,Sb doping can effectively optimize the carrier concentration and increase the carrier effective mass,while introducing point defects and stacking faults to further scatter the phonon transport and decrease the thermal conductivity.Consequently,a peak power factor of 22.37μW cm−1 K−2 is obtained at 703 K and a maximum thermoelectric figure of merit of 1.53 is achieved at 673 K,which are substantially larger than the values reported in the existing literature.A flexible thermoelectric generator is designed and fabricated using Sb-doped GeTe films deposited on polyimide and achieves a maximum output power density of 2.22×103 W m−2 for a temperature difference of 300 K.展开更多
The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristi...The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristics of the PCM clearly indicate that four states can be stored in this stacked film structure. Qualitative analysis indicates that the multiple-state storage capability of this stacked film structure is due to successive crystallizations in different Si-Sb-Te layers triggered by different amplitude currents.展开更多
Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of t...Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.展开更多
Doped with Sb and Te, Mg2Si based compounds were prepared respectively by solid state reaction at 823 K for 8 h. Effects of dopants of Sb and Te on the structure and thermoelectric properties of the compounds were inv...Doped with Sb and Te, Mg2Si based compounds were prepared respectively by solid state reaction at 823 K for 8 h. Effects of dopants of Sb and Te on the structure and thermoelectric properties of the compounds were investigated. By calculating the values of the electrical conductivity for Sb-doped sample, the mechanism of electric conduction at 625 K is different. The figure of merit for sample doped with 0.4 wt% Te at500K is 2.4 × 10-3W/mK2,and it reaches 3. 3 ×10-3 W/mK2 at 650K for the sample doped with 0. 5wt% Sb. The values are more than 1.4 times and 2.3 times of the pure Mg2 Si sample.展开更多
Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvas...Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvasive and nondestructivedetections [1–4]. Recently, the phosphors-converted NIR lightemittingdiodes (LEDs) based on “blue LED chips + broadbandNIR phosphors” are widely developed for next-generation costeffectiveNIR light sources. In this respect, the performance ofNIR phosphors directly determines the overall quality of phosphors-converted NIR LEDs. Therefore, the development ofefficient, blue LED-excitable, broadband NIR phosphors ishighly demanded. Current research works on broadband NIRphosphors mainly focus on Cr^(3+) and Eu^(2+) activated inorganiccompounds, but Cr3+-activated NIR phosphors might showpotential carcinogenic risk owing to the presence of Cr6+ byproduct,while Eu2+-activated NIR phosphors still suffer fromlow luminescence efficiency [5]. As a result, new alternativeenvironmentally-friendly broadband NIR phosphors areurgently needed. In recent years, lead-free metal halides havearoused widespread interest for lighting and displays because oftheir fascinating visible emissions [6–8];however, their NIRluminescence has not received enough attention. Moreover, thecurrently developed NIR-emitting lead-free metal halides exhibitsome disadvantages including low emission efficiency and theirlimited excitation wavelengths in the ultraviolet (UV) range.Until now, finding an efficient, blue LED-pumped, broadbandNIR-emitting lead-free metal halide remains a formidablechallenge.展开更多
Antimony doped tin oxide（ATO） thin films have been prepared by pulsed laser deposition（PLD） method.The intrinsic effect of Sb dopant,including the Sb content,transition degree between Sb（3＋） and Sb（5＋） and c...Antimony doped tin oxide（ATO） thin films have been prepared by pulsed laser deposition（PLD） method.The intrinsic effect of Sb dopant,including the Sb content,transition degree between Sb（3＋） and Sb（5＋） and crystallinity on the electrical and optical properties of the ATO thin films is mainly investigated.It is suggested that the transition degree of Sb（3＋） towards Sb（5＋）（Sb（5＋）/Sb（3＋） ratio） is determined by Sb content.When the Sb content is increased to 12 at%,the Sb（5＋）/Sb（3＋） ratio reaches the highest value of 2.05,corresponding to the resistivity of 2.70×10（-3） Ω·cm.Meanwhile,the Burstein-Moss effect caused by the increase of carrier concentration is observed and the band gap of the ATO thin films is broadened to 4.0 eV when the Sb content is increased to 12 at%,corresponding to the highest average optical transmittance of 92%.Comprehensively considering the combination of electrical and optical properties,the ATO thin films deposited with Sb content of 12 at%exhibit the best properties with the highest ＂figure of merit＂ of 3.85×10（-3） Ω（-1）.Finally,an antimony selenide（Sb_2Se_3） heterojunction solar cell prototype with the ATO thin film as the anode has been prepared,and a power conversion efficiency of 0.83%has been achieved.展开更多
Pristine GeTe shows inferior thermoelectric performance around unit due to the large carrier concentration induced by the presence of intrinsic high concentration of Ge vacancy. In this study, we report a thermoelectr...Pristine GeTe shows inferior thermoelectric performance around unit due to the large carrier concentration induced by the presence of intrinsic high concentration of Ge vacancy. In this study, we report a thermoelectric figure of merit ZT of 1.56 at 700 K, realized in Sb-doped GeTe based thermoelectric(TE)materials via combined effect of suppression of intrinsic Ge vacancy and Sb doping. The nonequilibrium nature during melt spinning process plays very important role. For one thing, it promotes the homogeneity in Ge_(1-x)Sb_xTe samples and refines the grain size of the product. Moreover the persistent Ge precipitated as impurity phase in the traditional synthesis process is found to be dissolved back into the GeTe sublattice, accompanying with a drastic suppression of Ge vacancies concentration which in combination with Sb electron doping significantly reduced the inherent carrier concentration in GeTe.Low carrier concentration, approaching the optimum carrier concentration ～3.74 × 10^(-20) cm^(-3) and a high power factor of 4.01 × 10^(-3) W m^(-1)K^(-2) at 750 K are achieved for Ge_(0.98)Sb_(0.02) Te sample. In addition,the enhanced grain boundary phonon scattering by refining the grain size through melt spinning(MS)process, coupled with the intensified alloying phonon scattering via Sb doping leads to low thermal conductivity of 1.53 W m^(-1) K^(-1) at 700 K for Ge_(0.94) Sb_(0.06) Te sample. All those contribute to a high ZT value,representing over 50% improvement in the ZT value compared to the Sb free samples, which provides an alternative way for ultrafast synthesis of high performance GeTe based thermoelectric material.展开更多
The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagne...The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.展开更多
All-inorganic perovskites,adopting cesium(Cs+)cation to completely replace the organic component of A-sites of hybrid organic–inorganic halide perovskites,have attracted much attention owing to the excellent thermal ...All-inorganic perovskites,adopting cesium(Cs+)cation to completely replace the organic component of A-sites of hybrid organic–inorganic halide perovskites,have attracted much attention owing to the excellent thermal stability.However,all-inorganic iodine-based perovskites generally exhibit poor phase stability in ambient conditions.Herein,we propose an efficient strategy to introduce antimony(Sb^(3+))into the crystalline lattices of CsPbI_(2)Br perovskite,which can effectively regulate the growth of perovskite crystals to obtain a more stable perovskite phase.Due to the much smaller ionic radius and lower electronegativity of trivalent Sb^(3+)than those of Pb^(2+),the Sb^(3+)doping can decrease surface defects and suppress charge recombination,resulting in longer carrier lifetime and negligible hysteresis.As a result,the all-inorganic perovskite solar cells(PSCs)based on 0.25%Sb^(3+)doped CsPbI_(2)Br light absorber and screen-printable nanocarbon counter electrode achieved a power conversion efficiency of 11.06%,which is 16%higher than that of the control devices without Sb^(3+)doping.Moreover,the Sb^(3+)doped all-inorganic PSCs also exhibited greatly improved endurance against heat and moisture.Due to the use of low-cost and easy-to-process nanocarbon counter electrodes,the manufacturing process of the all-inorganic PSCs is very convenient and highly repeatable,and the manufacturing cost can be greatly reduced.This work offers a promising approach to constructing high-stability all-inorganic PSCs by introducing appropriate lattice doping.展开更多
A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO ca...A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO can dramatically improve the dropping point and reduce contact resistance.The tribological properties of the new conductive grease were investigated using the MFT-R4000 reciprocating friction and wear tester.The tribol-test results indicate that ATO can dramatically improve the tribological properties of the grease.When the ATO concentration is 0.1wt%,the grease demonstrates the best friction reduction properties;when the concentration is 0.5wt%,the grease demonstrates the best anti-wear properties.The worn surfaces were observed and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy,and the friction mechanisms for the new conductive grease are proposed.The excellent tribological properties of the new conductive grease are attributed to the mechanical effect of ATO,and the film formed by Sn and Sb elements or metallic oxide deposited on worn surfaces during the friction process.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.12204355,52272210,12364006 and 12164011)the Open Project of State Key Laboratory of Superhard Materials,Jilin University(No.202110)the Natural Science Foundation of Shandong Province(Nos.ZR2022QA018,ZR2023QE282,ZR2023ME001 and ZR2023MF081)
文摘GeTe-based alloys are promising thermoelectric materials for use at medium temperatures owing to their excellent thermoelectric performance.In this study,Ge_(0.8-x)Mn_(0.1)Pb_(0.1)Sb_(x)Te alloys were obtained via vacuum melting and hot-press sintering.Sb doping effectively decreased the carrier concentration,resulting in an enhancement of the Seebeck coefficient and consequently imparting excellent electrical transport performance to the sample.With doping concentration increasing,the structure of the sample changed from rhombohedral to cubic,creating a more favorable band structure for electronic transport properties.The incorporation of Sb into GeTe intensifies the lattice defects within the material.The significant decrease in the lattice thermal conductivity of the Ge_(0.71)Mn_(0.1)Pb_(0.1)Sb_(0.09)Te alloy to 0.84 W m^(-1)K^(-1)at 323 K is primarily attributed to the phonon scattering effect emanating from the presence of edge dislocation,point defects,and inherent grain boundaries.Finally,the maximum ZT value of the Ge_(0.74)Mn_(0.1)Pb_(0.1)Sb_(0.06)Te alloy was~1.53773 K,which is a significant enhancement of 0.35 compared to the undoped Ge_(0.8)Mn_(0.1)Pb_(0.1)Te alloy.This substantial improvement underscores the positive impact of the selected doping elements and their concentrations on the overall thermoelectric performance of the alloy.
基金supported by the Anhui Province Natural Science Foundation for Excellent Youth Scholars(2208085Y17)the University Synergy Innovation Program of Anhui Province(GXXT-2022-008+1 种基金GXXT-2021-022)the Anhui Key Lab of Metal Material and Processing Open Project.
文摘Doping modification is one of the most effective ways to optimize the thermoelectric properties of Bi_(2)Te_(3)-based alloys.P-type Bi_(2−x)Sb_(x)Te_(3) thermoelectric materials have been successfully prepared by direct Sb doping method.It can be found that doping Sb into Bi_(2)Te_(3) lattice array for Bi-site replacement facilitates the generation of Sb′Te anti-site defects.This anti-site defects can increase the hole concentration and optimize electrical transport properties of Bi_(2−x)Sb_(x)Te_(3) alloys.In addition,the point defects induced by mass and stress fluctuations and the Sb impurities produced during the sintering process can enhance the multi-scale phonon scattering and reduce the lattice thermal conductivity.As a result,the Bi_(0.47)Sb_(1.63)Te_(3) sample has a maximum thermoelectric figure of merit ZT of 1.04 at 350 K.It is worth noting that the bipolar effect of Bi_(2)Te_(3)-based alloys can be weakened with the increase of Sb content.The Bi_(0.44)Sb_(1.66)Te_(3) sample has a maximum average ZT value(0.93)in the temperature range of 300–500 K,indicating that direct doping of Sb can broaden the temperature range corresponding to the optimal ZT value.This work provides an idea for developing high-performance near room temperature thermoelectric materials with a wide temperature range.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60976069)the Natural Science Foundation of Shaanxi Province, China (Grant No. 2010JM6008)the Xi’an Scientific and Technological Project, China (GrantNo. CXY1008)
文摘Chrysanthemum-like ZnO nanowire clusters with different Sb-doping concentrations were prepared using a hy- drothermal process. The microstructures, morphologies, and dielectric properties of the as-prepared products were characterized by X-ray diffraction （XRD）, high-resolution transmission electron microscopy （HRTEM）, field emission environment scanning electron microscope （FEESEM）, and microwave vector network analyzer respectively. The results indicate that the as-prepared products are Sb-doped ZnO single crystallines with a hexagonal wurtzite structure, the flower bud saturation degree Fd is obviously different from that of the pure ZnO nanowire clusters, the good dielectric loss property is found in Sb-doped ZnO products with low density, and the dielectric loss tangent tanSe increases with the increase of the Sb-doping concentration in a certain concentration range.
基金financial support from the Ministry of Science and Technology of China(Nos.2017YFA0700702,2017YFA0700705)the National Natural Science Foundation of China(Nos.52073290,51927803)+2 种基金the Liaoning Province Science and Technology Plan Project(2022-MS-011)the Science Fund for Distinguished Young Scholars of Liaoning Province(2023JH6/100500004)the Science and Technology Plan Projects of Shenyang(No.21108901).
文摘GeTe-based materials have attracted significant attention as high-efficiency thermoelectric materials for mid-temperature applications.However,GeTe thin-film materials with thermoelectric performances comparable to that of their bulk counterparts have not yet been reported,because of their unsatisfactory electrical and thermal properties caused by their poor crystal quality and high carrier concentration.Herein,a series of Sb-doped GeTe films and devices with remarkable thermoelectric performances are presented.These films are prepared through magnetron sputtering deposition at 553 K and exhibit a unique microstructure that consists of coarse-and fine-sized grains with high crystallization quality.The fine grains enhance the scattering associated with phonon transport and the coarse grains provide electron transport channels,which can suppress the thermal conductivity without obviously sacrificing the electrical conductivity.Moreover,Sb doping can effectively optimize the carrier concentration and increase the carrier effective mass,while introducing point defects and stacking faults to further scatter the phonon transport and decrease the thermal conductivity.Consequently,a peak power factor of 22.37μW cm−1 K−2 is obtained at 703 K and a maximum thermoelectric figure of merit of 1.53 is achieved at 673 K,which are substantially larger than the values reported in the existing literature.A flexible thermoelectric generator is designed and fabricated using Sb-doped GeTe films deposited on polyimide and achieves a maximum output power density of 2.22×103 W m−2 for a temperature difference of 300 K.
文摘The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristics of the PCM clearly indicate that four states can be stored in this stacked film structure. Qualitative analysis indicates that the multiple-state storage capability of this stacked film structure is due to successive crystallizations in different Si-Sb-Te layers triggered by different amplitude currents.
基金financially supported by the National Natural Science Foundation of China (No. 51364024 and 51404124)Gansu Province Department of Education Fund (No. 2013A-029)the Foundation of State Key Laboratory of Gansu Advanced Nonferrous Metal Materials (Nos. SKL 1316 and SKL 1314)
文摘Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.
文摘Doped with Sb and Te, Mg2Si based compounds were prepared respectively by solid state reaction at 823 K for 8 h. Effects of dopants of Sb and Te on the structure and thermoelectric properties of the compounds were investigated. By calculating the values of the electrical conductivity for Sb-doped sample, the mechanism of electric conduction at 625 K is different. The figure of merit for sample doped with 0.4 wt% Te at500K is 2.4 × 10-3W/mK2,and it reaches 3. 3 ×10-3 W/mK2 at 650K for the sample doped with 0. 5wt% Sb. The values are more than 1.4 times and 2.3 times of the pure Mg2 Si sample.
文摘Broadband near-infrared (NIR) light sources hold promise forsome important NIR spectroscopy applications such as nightvision, plant growths, optical communications, remote sensing,biomedical imaging and other noninvasive and nondestructivedetections [1–4]. Recently, the phosphors-converted NIR lightemittingdiodes (LEDs) based on “blue LED chips + broadbandNIR phosphors” are widely developed for next-generation costeffectiveNIR light sources. In this respect, the performance ofNIR phosphors directly determines the overall quality of phosphors-converted NIR LEDs. Therefore, the development ofefficient, blue LED-excitable, broadband NIR phosphors ishighly demanded. Current research works on broadband NIRphosphors mainly focus on Cr^(3+) and Eu^(2+) activated inorganiccompounds, but Cr3+-activated NIR phosphors might showpotential carcinogenic risk owing to the presence of Cr6+ byproduct,while Eu2+-activated NIR phosphors still suffer fromlow luminescence efficiency [5]. As a result, new alternativeenvironmentally-friendly broadband NIR phosphors areurgently needed. In recent years, lead-free metal halides havearoused widespread interest for lighting and displays because oftheir fascinating visible emissions [6–8];however, their NIRluminescence has not received enough attention. Moreover, thecurrently developed NIR-emitting lead-free metal halides exhibitsome disadvantages including low emission efficiency and theirlimited excitation wavelengths in the ultraviolet (UV) range.Until now, finding an efficient, blue LED-pumped, broadbandNIR-emitting lead-free metal halide remains a formidablechallenge.
基金Funded by the International Science&Technology Cooperation Program of China(No.2011DFA52650)the"111"Project(No.B13035)+1 种基金the National Natural Science Foundation of China(No.51521001)the Fundamental Research Funds for the Central Universities
文摘Antimony doped tin oxide（ATO） thin films have been prepared by pulsed laser deposition（PLD） method.The intrinsic effect of Sb dopant,including the Sb content,transition degree between Sb（3＋） and Sb（5＋） and crystallinity on the electrical and optical properties of the ATO thin films is mainly investigated.It is suggested that the transition degree of Sb（3＋） towards Sb（5＋）（Sb（5＋）/Sb（3＋） ratio） is determined by Sb content.When the Sb content is increased to 12 at%,the Sb（5＋）/Sb（3＋） ratio reaches the highest value of 2.05,corresponding to the resistivity of 2.70×10（-3） Ω·cm.Meanwhile,the Burstein-Moss effect caused by the increase of carrier concentration is observed and the band gap of the ATO thin films is broadened to 4.0 eV when the Sb content is increased to 12 at%,corresponding to the highest average optical transmittance of 92%.Comprehensively considering the combination of electrical and optical properties,the ATO thin films deposited with Sb content of 12 at%exhibit the best properties with the highest ＂figure of merit＂ of 3.85×10（-3） Ω（-1）.Finally,an antimony selenide（Sb_2Se_3） heterojunction solar cell prototype with the ATO thin film as the anode has been prepared,and a power conversion efficiency of 0.83%has been achieved.
基金supported by the National Natural Science Foundation of China(51402222,51521001,and 51632006)the 111 Project of China(B07040)
文摘Pristine GeTe shows inferior thermoelectric performance around unit due to the large carrier concentration induced by the presence of intrinsic high concentration of Ge vacancy. In this study, we report a thermoelectric figure of merit ZT of 1.56 at 700 K, realized in Sb-doped GeTe based thermoelectric(TE)materials via combined effect of suppression of intrinsic Ge vacancy and Sb doping. The nonequilibrium nature during melt spinning process plays very important role. For one thing, it promotes the homogeneity in Ge_(1-x)Sb_xTe samples and refines the grain size of the product. Moreover the persistent Ge precipitated as impurity phase in the traditional synthesis process is found to be dissolved back into the GeTe sublattice, accompanying with a drastic suppression of Ge vacancies concentration which in combination with Sb electron doping significantly reduced the inherent carrier concentration in GeTe.Low carrier concentration, approaching the optimum carrier concentration ～3.74 × 10^(-20) cm^(-3) and a high power factor of 4.01 × 10^(-3) W m^(-1)K^(-2) at 750 K are achieved for Ge_(0.98)Sb_(0.02) Te sample. In addition,the enhanced grain boundary phonon scattering by refining the grain size through melt spinning(MS)process, coupled with the intensified alloying phonon scattering via Sb doping leads to low thermal conductivity of 1.53 W m^(-1) K^(-1) at 700 K for Ge_(0.94) Sb_(0.06) Te sample. All those contribute to a high ZT value,representing over 50% improvement in the ZT value compared to the Sb free samples, which provides an alternative way for ultrafast synthesis of high performance GeTe based thermoelectric material.
基金This work was supported by tile National Natural Science Foundation of China （Grant Nos. U1432135, 11674054, 11474080, and 11611140101） and the Scientific Research Foundation of Graduate School of Southeast University （Grant No. YBJJ1621）. X. Xu would also like to acknowledge the National Key Basic Research Program of China （Grant No. 2014CB648400） and the support from the Distinguished Young Scientist Funds of Zhejiang Province （No. LR14A040001）.
文摘The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.
基金support of the National Key R&D Program of China(No.2017YFA0208200)the National Natural Science Foundation of China(Nos.22022505 and 21872069)+3 种基金the Fundamental Research Funds for the Central Universities(Nos.020514380266,020514380272,and 020514380274)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province(No.BK20220008)the Nanjing International Collaboration Research Program(Nos.202201007 and 2022SX00000955)the Suzhou Gusu Leading Talent Program of Science and Technology Innovation and Entrepreneurship in Wujiang District(No.ZXL2021273).
文摘All-inorganic perovskites,adopting cesium(Cs+)cation to completely replace the organic component of A-sites of hybrid organic–inorganic halide perovskites,have attracted much attention owing to the excellent thermal stability.However,all-inorganic iodine-based perovskites generally exhibit poor phase stability in ambient conditions.Herein,we propose an efficient strategy to introduce antimony(Sb^(3+))into the crystalline lattices of CsPbI_(2)Br perovskite,which can effectively regulate the growth of perovskite crystals to obtain a more stable perovskite phase.Due to the much smaller ionic radius and lower electronegativity of trivalent Sb^(3+)than those of Pb^(2+),the Sb^(3+)doping can decrease surface defects and suppress charge recombination,resulting in longer carrier lifetime and negligible hysteresis.As a result,the all-inorganic perovskite solar cells(PSCs)based on 0.25%Sb^(3+)doped CsPbI_(2)Br light absorber and screen-printable nanocarbon counter electrode achieved a power conversion efficiency of 11.06%,which is 16%higher than that of the control devices without Sb^(3+)doping.Moreover,the Sb^(3+)doped all-inorganic PSCs also exhibited greatly improved endurance against heat and moisture.Due to the use of low-cost and easy-to-process nanocarbon counter electrodes,the manufacturing process of the all-inorganic PSCs is very convenient and highly repeatable,and the manufacturing cost can be greatly reduced.This work offers a promising approach to constructing high-stability all-inorganic PSCs by introducing appropriate lattice doping.
基金supported by Hundreds Talent Program of Chinese Academy of Science.
文摘A new conductive grease was synthesized using a nanometer powder,i.e.,Sb doped SnO2(ATO),as an additive.The typical properties of this new conductive grease were investigated in detail.The results indicate that ATO can dramatically improve the dropping point and reduce contact resistance.The tribological properties of the new conductive grease were investigated using the MFT-R4000 reciprocating friction and wear tester.The tribol-test results indicate that ATO can dramatically improve the tribological properties of the grease.When the ATO concentration is 0.1wt%,the grease demonstrates the best friction reduction properties;when the concentration is 0.5wt%,the grease demonstrates the best anti-wear properties.The worn surfaces were observed and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy,and the friction mechanisms for the new conductive grease are proposed.The excellent tribological properties of the new conductive grease are attributed to the mechanical effect of ATO,and the film formed by Sn and Sb elements or metallic oxide deposited on worn surfaces during the friction process.
