Some cobalt antimonides have been prepared and studied as the candidate anodematerials for lithium ion batteries. Reversible capacities of 424,423 and 546 mA.h.g^(-1) weremeasured at the first cycle for as-solidified ...Some cobalt antimonides have been prepared and studied as the candidate anodematerials for lithium ion batteries. Reversible capacities of 424,423 and 546 mA.h.g^(-1) weremeasured at the first cycle for as-solidified CoSb_2, CoSb_3 and annealed CoSb_3 respectively. A lowlithium ions diffusion coefficient in the order of 10^(16) m^2.s^(-1) was estimated from thecoulometric titration measurements in the annealed CoSb_3 electrode. It was found that theelectrochemical properties of fine powders are significantly better than coarse powders. However theSEM picture shows that the nano-sized CoSb_3 powders gathered to larger granules, which worsenssomewhat the capacity retention of the nano-sized materials, although the volume capacities of theannealed and ball milled CoSb_3 remain near twice of that of graphite after 50 cycles.展开更多
In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated...In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.展开更多
The kinetics of MOCVD GaInAsSb and AlGaAsSb was studied by the growth rate as a function of growth temperature and partial pressure of Ⅲ and Ⅴ MO species. The diffusion theory was used to explain the mass transport ...The kinetics of MOCVD GaInAsSb and AlGaAsSb was studied by the growth rate as a function of growth temperature and partial pressure of Ⅲ and Ⅴ MO species. The diffusion theory was used to explain the mass transport processes in MOCVD Ⅲ Ⅴ quaternary antimonides. On the basis of the discussion about their growth kinetics and epilayer properties, the good quality multi epilayers of these two quaternary antimonides and their photodetectors and arrays with wavelength of 1.8～2.3 μm and detectivities of D *>10 9 cm Hz 1/2 W -1 were obtained.展开更多
Thermal parameters of various III-V antimonides,especially the quaternary lattice matched to GaSb or InAs substrates as well as some strained ternaries,have been investigated theoretically.Results show that at most co...Thermal parameters of various III-V antimonides,especially the quaternary lattice matched to GaSb or InAs substrates as well as some strained ternaries,have been investigated theoretically.Results show that at most composition region many ternary and quaternary antimonides exhibit rather lower thermal conductivity compared to related binaries,and the reason has been discussed.The thermal designing rule of the lasers and other power devices using those antimonides also has been discussed.展开更多
This article reports the results of our investigations on electronic and transport properties of zinc blende gallium antimonide (zb-GaSb). Our ab-initio, self-consistent and non-relativistic calculations used a local ...This article reports the results of our investigations on electronic and transport properties of zinc blende gallium antimonide (zb-GaSb). Our ab-initio, self-consistent and non-relativistic calculations used a local density approximation potential (LDA) and the linear combination of atomic orbital formalism (LCAO). We have succeeded in performing a generalized minimization of the energy, using the Bagayoko, Zhao and Williams (BZW) method, to reach the ground state of the material while avoiding over-complete basis sets. Consequently, our results have the full physical content of density functional theory (DFT) and agree with available, corresponding experimental data. Using an experimental room temperature lattice constant of 6.09593?, we obtained a direct band gap of 0.751 eV, in good agreement with room temperature measurements. Our results reproduced the experimental locations of the peaks in the total density of valence states as well as the measured electron and hole effective masses. Hence, this work points to the capability of ab-initio DFT calculations to inform and to guide the design and the fabrication of semiconductor based devices—provided a generalized minimization of the energy is performed.展开更多
Various nanophotonic devices based on semiconductor wires with a diameter of several ten nanometers have been studied.Nevertheless,studying the optoelectronics properties and performance of such devices based on large...Various nanophotonic devices based on semiconductor wires with a diameter of several ten nanometers have been studied.Nevertheless,studying the optoelectronics properties and performance of such devices based on large-diameter wires is interesting and meaningful.Here,we successfully grew the micronsized indium antimonide(InSb) wires,and examined their nonlinear optical properties by Z-scan and I-scan(power-dependent) methods within the wavelength range of 0.8-2.8 μm.Furthermore,we demonstrated InSb micro wires(MWs) working as an effective and robust optical switch within 1-2.8 μm wavelength.The findings can open possibilities for research on more large-diameter MWs made from other semiconductor materials for photonic and electronic devices.展开更多
Embedded phase-change random-access memory(ePCRAM)applications demand superior data retention in amorphous phase-change materials(PCMs).Traditional PCM design strategies have focused on enhancing the thermal stability...Embedded phase-change random-access memory(ePCRAM)applications demand superior data retention in amorphous phase-change materials(PCMs).Traditional PCM design strategies have focused on enhancing the thermal stability of the amorphous phase,often at the expense of the crystallization speed.While this approach supports reliable microchip operations,it compromises the ability to achieve rapid responses.To address this limitation,we modified ultrafast-crystallizing Sb thin films by incorporating Sc dopants,achieving the highest 10-year retention temperature(~175℃)among binary antimonide PCMs while maintaining a sub-10-ns SET operation speed.This reconciliation of two seemingly contradictory properties arises from the unique kinetic features of the 5-nm-thick Sc12Sb88 films,which exhibit an enlarged fragile-to-strong crossover in viscosity at medium supercooled temperature zones and an incompatible sublattice ordering behavior between the Sc and Sb atoms.By tailoring the crystallization kinetics of PCMs through strategic doping and nanoscale confinement,we provide new opportunities for developing robust yet swift ePCRAMs.展开更多
An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one p...An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.展开更多
Resistivity, magnetoresistivity and Hall effect measurements in n-type Te-doped GaSb grown by the liquid encapsuled Czochralski technique are carried out as functions of temperature （35-350 K） and magnetic field （0...Resistivity, magnetoresistivity and Hall effect measurements in n-type Te-doped GaSb grown by the liquid encapsuled Czochralski technique are carried out as functions of temperature （35-350 K） and magnetic field （0-1.35 T）. The power law model is used to explain the temperature-dependent resistivity. The magnetic-field-dependent data are analysed using the quantitative mobility spectrum analysis technique. The effect of individual band parameters （nL, nr, μL, μr, p and μp） on both the electron and magneto transports have been discussed. The EL - Er energy separation between the L and conduction band edges is also derived.展开更多
RE 3Cu 3Sb 4(RE=Nd, Sm, Tb, Dy, Ho) was synthesized by arc melting method and their crystal structures were characterized by powder X ray method. The compounds crystallize in cubic system, Y 3Au 3Sb 4 type, sp...RE 3Cu 3Sb 4(RE=Nd, Sm, Tb, Dy, Ho) was synthesized by arc melting method and their crystal structures were characterized by powder X ray method. The compounds crystallize in cubic system, Y 3Au 3Sb 4 type, space group I43d (No.220), Pearson code cI40. The unit cell parameters are: Nd 3Cu 3Sb 4: a =0 96749(1) nm, V =0 90561(3) nm 3; Sm 3Cu 3Sb 4: a =0 96145(1) nm, V =0 88875(3) nm 3; Tb 3Cu 3Sb 4: a =0 95362(1) nm, V =0 86721(3) nm 3; Dy 3Cu 3Sb 4: a =0 95088(1) nm, V =0 85975(3) nm 3; Ho 3Cu 3Sb 4: a =0 9488(2) nm, V =0 8541(5) nm 3; Z =4. The structures are characterized by covalent bonded Cu Sb tetrahedra which form three dimensional networks by sharing corners. The rare earth atoms are distributed in the cages. The formula with the charge balance can be written as RE 3+ 3Cu 1+ 3Sb 3- 4 which are metallic Zintl phases having the weak metallic conductivity. The bonds have typical transitional features. General atomic coordination environment rules are followed. The unit cell parameters show the lanthanide contraction.展开更多
Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed f...Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed for the growth of bulk crystals, without the seed, without contact to the ampoule wall, without coating and without external pressure. An automated furnace was designed and fabricated for the controlled temperature gradients, growth conditions and parameters. The typical ingots growths of GaSb have shown the gap of 20 μm-145 μm and mobility μn = 1125 cm^2/V.sec at 300 K. Mobility is highest and five times larger than the attached growths. Dislocation density is the order of 104/cm2 in the conical region, decreases in the direction of growth, and in many crystals reached less than 103/cm2. The spontaneous gap formation due to the meniscus depends on the pressure differences and thermal state. GaSb grown ingots have shown progress in the properties of crystal grown ever, and attributed to reduce thermal stress without contact to the ampoule wall.展开更多
The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electr...The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD values. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high performance of 2.3 μm photodetectors were achieved only when the good quality GaSb wafers was used as the substrates.展开更多
Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion seconda...Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion secondary batteries wereinvestigated. It was found that they exhibited significantly larger volumetric capacity than carbon-based materi-als. The formation and composition of solid electrolyte interface (SEI) film were characterized by electrochemicalimpedance spectroscopy (EIS) and Fourier transform infra-red (FTIR) spectroscopy.展开更多
This paper examines GaSb short-wavelength infrared detectors employing planar PN junctions. The fabrication was based on the Zn diffusion process and the diffusion temperature was optimized. Characterization revealed ...This paper examines GaSb short-wavelength infrared detectors employing planar PN junctions. The fabrication was based on the Zn diffusion process and the diffusion temperature was optimized. Characterization revealed a 50% cut-off wavelength of 1.73 μm, a maximum detectivity of 8.73 × 10^(10) cm·Hz^(1/2)/W, and a minimum dark current density of 1.02 × 10^(-5) A/cm^(2).Additionally, a maximum quantum efficiency of 60.3% was achieved. Subsequent optimization of fabrication enabled the realization of a 320 × 256 focal plane array that exhibited satisfactory imaging results. Remarkably, the GaSb planar detectors demonstrated potential in low-cost short wavelength infrared imaging, without requiring material epitaxy or deposition.展开更多
A1Sb/InAs quantum well （QW） structures and InAs films on GaAs （001） substrates were grown by molecular beam epitaxy （MBE）. We investigated the dependence of electron mobility and two-dimensional electron gas （2...A1Sb/InAs quantum well （QW） structures and InAs films on GaAs （001） substrates were grown by molecular beam epitaxy （MBE）. We investigated the dependence of electron mobility and two-dimensional electron gas （2DEG） concen- tration on the thickness of an InAs Channel. It is found that electron mobility as high as 19050 cm2 · V-1 · s-1 has been achieved for an InAs channel of 22.5 nm. The Hall devices with high sensitivity and good temperature stability were fabricated based on the A1Sb/InAs QW structures. Their sensitivity is markedly superior to Hall devices of InAs films.展开更多
Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. Th...Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.展开更多
Since 1994, the vertical directional solidification （VDS） technique is employed for the growths of bulk crystals-without the seed, without contact to the ampoule wall, without coating and without external pressure, ...Since 1994, the vertical directional solidification （VDS） technique is employed for the growths of bulk crystals-without the seed, without contact to the ampoule wall, without coating and without external pressure, which leads to the detached growth. Growth velocities ranged from 3 mm/h to 10 mm/h, and rotation rates 10-20 rpm have been used. Ingots, 10-20 mm diameter and 60-65 mm length, have been grown with the conical ampoule geometry and these ingots have shown symmetric detachment. Crystals grown under such conditions showed the relatively low dislocation density and the highest carrier mobility,/tn = 5.9 x 104 cm2＂Vl-sl than the crystal grown ever. For the detached crystals, the dislocation density is 104 cm＂2 in conical region, and reached less than 103 cm-2 in the direction of the growth, when the ingots are not in contact with the ampoule wall. Experiments for indium-antimonide （InSb） growth have shown that the 80% growth environments have detachment, 15% entrapped in conical region and 5% attached.展开更多
Power scaling in conventional broad-area(BA)lasers often leads to the operation of higher-order lateral modes,resulting in a multiple-lobe far-field profile with large divergence.Here,we report an advanced sawtooth wa...Power scaling in conventional broad-area(BA)lasers often leads to the operation of higher-order lateral modes,resulting in a multiple-lobe far-field profile with large divergence.Here,we report an advanced sawtooth waveguide(ASW)structure integrated onto a wide ridge waveguide.It strategically enhances the loss difference between higher-order modes and the fundamental mode,thereby facilitating high-power narrow-beam emission.Both optical simulations and experimental results illustrate the significant increase in additional scattering loss of the higher-order modes.The optimized ASW lasers achieve an impressive output power of 1.1 W at 4.6 A at room temperature,accompanied by a minimal full width at half maximum lateral divergence angle of 4.91°.Notably,the far-field divergence is reduced from19.61° to 11.39° at the saturation current,showcasing a remarkable 42%improvement compared to conventional BA lasers.Moreover,the current dependence of divergence has been effectively improved by 38%,further confirming the consistent and effective lateral mode control capability offered by our design.展开更多
A single gate Ⅲ-Ⅴ junctionless tunnel field effect transistor（SG-JLTFET） has been reported which shows excellent dc characteristics at low power supply operation.This device has a thin uniformly n-type doped chann...A single gate Ⅲ-Ⅴ junctionless tunnel field effect transistor（SG-JLTFET） has been reported which shows excellent dc characteristics at low power supply operation.This device has a thin uniformly n-type doped channel of GaSb i.e.gallium antimonide which is grown epitaxially over silicon substrate.The DC performance parameters such as I（on）,I（on）/I（off）,average and point subthreshold slope as well as device parameters for analog applications viz.transconductance gm,transconductance generation efficiency gm/ID,various capacitances and the unity gain frequency fT are studied using a device simulator.Along with examining its endurance to short channel effects,the performances are also compared with a Silicon Dual Gate Junctionless Tunnel FET（DG-JLTFET）.The DC and small signal analog performance reflects that GaSb SG-JLTFET has immense purview for extreme high-frequency and low-power applications.展开更多
Five-period AlGaSb/GaSb multiple quantum wells（MQW） are grown on a GaSb buffer.Through optimizing the AlSb nucleation layer,the low threading dislocation density of the MQW is found to be（2.50±0.91）×10~8...Five-period AlGaSb/GaSb multiple quantum wells（MQW） are grown on a GaSb buffer.Through optimizing the AlSb nucleation layer,the low threading dislocation density of the MQW is found to be（2.50±0.91）×10~8 cm^（-2） in 1-μm GaSb buffer,as determined by plan-view transmission election microscopy（TEM） images.High resolution TEM clearly shows the presence of 90°misfit dislocations with an average spacing of 5.4 nm at the AlSb/GaAs interface,which effectively relieve most of the strain energy.In the temperature range from T = 26 K to 300 K,photoluminescence of the MQW is dominated by the ground state electron to ground state heavy hole（el-hhl） transition, while a high energy shoulder clearly seen at T76 K can be attributed to the ground state electron to ground state light hole（el-lhl） transition.展开更多
基金This work is financially supported by the National Natural Science Foundation of China(No.59771032)RFDP of the Education Ministry of China (No.97033518 and 20010335045)
文摘Some cobalt antimonides have been prepared and studied as the candidate anodematerials for lithium ion batteries. Reversible capacities of 424,423 and 546 mA.h.g^(-1) weremeasured at the first cycle for as-solidified CoSb_2, CoSb_3 and annealed CoSb_3 respectively. A lowlithium ions diffusion coefficient in the order of 10^(16) m^2.s^(-1) was estimated from thecoulometric titration measurements in the annealed CoSb_3 electrode. It was found that theelectrochemical properties of fine powders are significantly better than coarse powders. However theSEM picture shows that the nano-sized CoSb_3 powders gathered to larger granules, which worsenssomewhat the capacity retention of the nano-sized materials, although the volume capacities of theannealed and ball milled CoSb_3 remain near twice of that of graphite after 50 cycles.
文摘In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.
文摘The kinetics of MOCVD GaInAsSb and AlGaAsSb was studied by the growth rate as a function of growth temperature and partial pressure of Ⅲ and Ⅴ MO species. The diffusion theory was used to explain the mass transport processes in MOCVD Ⅲ Ⅴ quaternary antimonides. On the basis of the discussion about their growth kinetics and epilayer properties, the good quality multi epilayers of these two quaternary antimonides and their photodetectors and arrays with wavelength of 1.8～2.3 μm and detectivities of D *>10 9 cm Hz 1/2 W -1 were obtained.
文摘Thermal parameters of various III-V antimonides,especially the quaternary lattice matched to GaSb or InAs substrates as well as some strained ternaries,have been investigated theoretically.Results show that at most composition region many ternary and quaternary antimonides exhibit rather lower thermal conductivity compared to related binaries,and the reason has been discussed.The thermal designing rule of the lasers and other power devices using those antimonides also has been discussed.
文摘This article reports the results of our investigations on electronic and transport properties of zinc blende gallium antimonide (zb-GaSb). Our ab-initio, self-consistent and non-relativistic calculations used a local density approximation potential (LDA) and the linear combination of atomic orbital formalism (LCAO). We have succeeded in performing a generalized minimization of the energy, using the Bagayoko, Zhao and Williams (BZW) method, to reach the ground state of the material while avoiding over-complete basis sets. Consequently, our results have the full physical content of density functional theory (DFT) and agree with available, corresponding experimental data. Using an experimental room temperature lattice constant of 6.09593?, we obtained a direct band gap of 0.751 eV, in good agreement with room temperature measurements. Our results reproduced the experimental locations of the peaks in the total density of valence states as well as the measured electron and hole effective masses. Hence, this work points to the capability of ab-initio DFT calculations to inform and to guide the design and the fabrication of semiconductor based devices—provided a generalized minimization of the energy is performed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 62005139, and 12174212)Natural Science Foundation of Shandong Province (Grant No. ZR2019MF061)+7 种基金the support of Aalto University Doctoral SchoolWalter Ahlstram FoundationElektroniikkainsinoorien SaatioSahkoinsinooriliiton SaatioNokia FoundationFinnish Foundation for Technology Promotion (Tekniikan Edistamissaatio)Waldemar von Frenckell’s FoundationKansallis-Osake-Pankki Fund。
文摘Various nanophotonic devices based on semiconductor wires with a diameter of several ten nanometers have been studied.Nevertheless,studying the optoelectronics properties and performance of such devices based on large-diameter wires is interesting and meaningful.Here,we successfully grew the micronsized indium antimonide(InSb) wires,and examined their nonlinear optical properties by Z-scan and I-scan(power-dependent) methods within the wavelength range of 0.8-2.8 μm.Furthermore,we demonstrated InSb micro wires(MWs) working as an effective and robust optical switch within 1-2.8 μm wavelength.The findings can open possibilities for research on more large-diameter MWs made from other semiconductor materials for photonic and electronic devices.
基金the National Natural Science Foundation of China(52032006)the Basic and Applied Basic Research Foundation of Guangdong(2020B1515120008)+1 种基金the Science and Technology Foundation of Shenzhen(ZDSYS20210623091813040)Shenzhen University 2035 Program for Excellent Research(00000203)。
文摘Embedded phase-change random-access memory(ePCRAM)applications demand superior data retention in amorphous phase-change materials(PCMs).Traditional PCM design strategies have focused on enhancing the thermal stability of the amorphous phase,often at the expense of the crystallization speed.While this approach supports reliable microchip operations,it compromises the ability to achieve rapid responses.To address this limitation,we modified ultrafast-crystallizing Sb thin films by incorporating Sc dopants,achieving the highest 10-year retention temperature(~175℃)among binary antimonide PCMs while maintaining a sub-10-ns SET operation speed.This reconciliation of two seemingly contradictory properties arises from the unique kinetic features of the 5-nm-thick Sc12Sb88 films,which exhibit an enlarged fragile-to-strong crossover in viscosity at medium supercooled temperature zones and an incompatible sublattice ordering behavior between the Sc and Sb atoms.By tailoring the crystallization kinetics of PCMs through strategic doping and nanoscale confinement,we provide new opportunities for developing robust yet swift ePCRAMs.
文摘An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.
文摘Resistivity, magnetoresistivity and Hall effect measurements in n-type Te-doped GaSb grown by the liquid encapsuled Czochralski technique are carried out as functions of temperature （35-350 K） and magnetic field （0-1.35 T）. The power law model is used to explain the temperature-dependent resistivity. The magnetic-field-dependent data are analysed using the quantitative mobility spectrum analysis technique. The effect of individual band parameters （nL, nr, μL, μr, p and μp） on both the electron and magneto transports have been discussed. The EL - Er energy separation between the L and conduction band edges is also derived.
文摘RE 3Cu 3Sb 4(RE=Nd, Sm, Tb, Dy, Ho) was synthesized by arc melting method and their crystal structures were characterized by powder X ray method. The compounds crystallize in cubic system, Y 3Au 3Sb 4 type, space group I43d (No.220), Pearson code cI40. The unit cell parameters are: Nd 3Cu 3Sb 4: a =0 96749(1) nm, V =0 90561(3) nm 3; Sm 3Cu 3Sb 4: a =0 96145(1) nm, V =0 88875(3) nm 3; Tb 3Cu 3Sb 4: a =0 95362(1) nm, V =0 86721(3) nm 3; Dy 3Cu 3Sb 4: a =0 95088(1) nm, V =0 85975(3) nm 3; Ho 3Cu 3Sb 4: a =0 9488(2) nm, V =0 8541(5) nm 3; Z =4. The structures are characterized by covalent bonded Cu Sb tetrahedra which form three dimensional networks by sharing corners. The rare earth atoms are distributed in the cages. The formula with the charge balance can be written as RE 3+ 3Cu 1+ 3Sb 3- 4 which are metallic Zintl phases having the weak metallic conductivity. The bonds have typical transitional features. General atomic coordination environment rules are followed. The unit cell parameters show the lanthanide contraction.
文摘Advantages of the detached phenomena have influenced researchers to modify the conventional methods to promote it on the earth. Since 1994, the vertical directional solidification （VDS） technique has been employed for the growth of bulk crystals, without the seed, without contact to the ampoule wall, without coating and without external pressure. An automated furnace was designed and fabricated for the controlled temperature gradients, growth conditions and parameters. The typical ingots growths of GaSb have shown the gap of 20 μm-145 μm and mobility μn = 1125 cm^2/V.sec at 300 K. Mobility is highest and five times larger than the attached growths. Dislocation density is the order of 104/cm2 in the conical region, decreases in the direction of growth, and in many crystals reached less than 103/cm2. The spontaneous gap formation due to the meniscus depends on the pressure differences and thermal state. GaSb grown ingots have shown progress in the properties of crystal grown ever, and attributed to reduce thermal stress without contact to the ampoule wall.
文摘The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD values. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high performance of 2.3 μm photodetectors were achieved only when the good quality GaSb wafers was used as the substrates.
基金This work is supported by the N ational Natural Science Foundation of China(No.50201014)RFDP of the Education Ministry of China(No.20010335045).
文摘Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion secondary batteries wereinvestigated. It was found that they exhibited significantly larger volumetric capacity than carbon-based materi-als. The formation and composition of solid electrolyte interface (SEI) film were characterized by electrochemicalimpedance spectroscopy (EIS) and Fourier transform infra-red (FTIR) spectroscopy.
文摘This paper examines GaSb short-wavelength infrared detectors employing planar PN junctions. The fabrication was based on the Zn diffusion process and the diffusion temperature was optimized. Characterization revealed a 50% cut-off wavelength of 1.73 μm, a maximum detectivity of 8.73 × 10^(10) cm·Hz^(1/2)/W, and a minimum dark current density of 1.02 × 10^(-5) A/cm^(2).Additionally, a maximum quantum efficiency of 60.3% was achieved. Subsequent optimization of fabrication enabled the realization of a 320 × 256 focal plane array that exhibited satisfactory imaging results. Remarkably, the GaSb planar detectors demonstrated potential in low-cost short wavelength infrared imaging, without requiring material epitaxy or deposition.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. ISCAS2009T04)the National Natural Science Foundation of China (Grant Nos. 61204012 and 61274049)+1 种基金the Beijing Natural Science Foundation, China (Grant No. 2112040)the Beijing Nova Program, China (Grant No. 2010B056)
文摘A1Sb/InAs quantum well （QW） structures and InAs films on GaAs （001） substrates were grown by molecular beam epitaxy （MBE）. We investigated the dependence of electron mobility and two-dimensional electron gas （2DEG） concen- tration on the thickness of an InAs Channel. It is found that electron mobility as high as 19050 cm2 · V-1 · s-1 has been achieved for an InAs channel of 22.5 nm. The Hall devices with high sensitivity and good temperature stability were fabricated based on the A1Sb/InAs QW structures. Their sensitivity is markedly superior to Hall devices of InAs films.
基金Project supported by the National High Technology Research and Development Program of China (Grant No 2005A000200)the West Light Plan of China (Grant No 2005ZD01)the Xi’an Applied Materials Innovation Fund of China (Grant No XA-AM-200613)
文摘Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.
文摘Since 1994, the vertical directional solidification （VDS） technique is employed for the growths of bulk crystals-without the seed, without contact to the ampoule wall, without coating and without external pressure, which leads to the detached growth. Growth velocities ranged from 3 mm/h to 10 mm/h, and rotation rates 10-20 rpm have been used. Ingots, 10-20 mm diameter and 60-65 mm length, have been grown with the conical ampoule geometry and these ingots have shown symmetric detachment. Crystals grown under such conditions showed the relatively low dislocation density and the highest carrier mobility,/tn = 5.9 x 104 cm2＂Vl-sl than the crystal grown ever. For the detached crystals, the dislocation density is 104 cm＂2 in conical region, and reached less than 103 cm-2 in the direction of the growth, when the ingots are not in contact with the ampoule wall. Experiments for indium-antimonide （InSb） growth have shown that the 80% growth environments have detachment, 15% entrapped in conical region and 5% attached.
基金supported by the National Natural Science Foundation of China(Grant No.62204238)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300801)+1 种基金‘Announce the list and take charge’of the Major Special Plan of Science and Technology in Shanxi Province(Grant No.202201030201009)the National Key R&D Program of China(Grant No.2019YFA0705203)。
文摘Power scaling in conventional broad-area(BA)lasers often leads to the operation of higher-order lateral modes,resulting in a multiple-lobe far-field profile with large divergence.Here,we report an advanced sawtooth waveguide(ASW)structure integrated onto a wide ridge waveguide.It strategically enhances the loss difference between higher-order modes and the fundamental mode,thereby facilitating high-power narrow-beam emission.Both optical simulations and experimental results illustrate the significant increase in additional scattering loss of the higher-order modes.The optimized ASW lasers achieve an impressive output power of 1.1 W at 4.6 A at room temperature,accompanied by a minimal full width at half maximum lateral divergence angle of 4.91°.Notably,the far-field divergence is reduced from19.61° to 11.39° at the saturation current,showcasing a remarkable 42%improvement compared to conventional BA lasers.Moreover,the current dependence of divergence has been effectively improved by 38%,further confirming the consistent and effective lateral mode control capability offered by our design.
文摘A single gate Ⅲ-Ⅴ junctionless tunnel field effect transistor（SG-JLTFET） has been reported which shows excellent dc characteristics at low power supply operation.This device has a thin uniformly n-type doped channel of GaSb i.e.gallium antimonide which is grown epitaxially over silicon substrate.The DC performance parameters such as I（on）,I（on）/I（off）,average and point subthreshold slope as well as device parameters for analog applications viz.transconductance gm,transconductance generation efficiency gm/ID,various capacitances and the unity gain frequency fT are studied using a device simulator.Along with examining its endurance to short channel effects,the performances are also compared with a Silicon Dual Gate Junctionless Tunnel FET（DG-JLTFET）.The DC and small signal analog performance reflects that GaSb SG-JLTFET has immense purview for extreme high-frequency and low-power applications.
基金supported by the National Natural Science Foundation of China(No.50572120)the National High Technology Research and Development Program of China(No.2009AA033101)the State Key Development for Basic Research of China(No.2010CB327501).
文摘Five-period AlGaSb/GaSb multiple quantum wells（MQW） are grown on a GaSb buffer.Through optimizing the AlSb nucleation layer,the low threading dislocation density of the MQW is found to be（2.50±0.91）×10~8 cm^（-2） in 1-μm GaSb buffer,as determined by plan-view transmission election microscopy（TEM） images.High resolution TEM clearly shows the presence of 90°misfit dislocations with an average spacing of 5.4 nm at the AlSb/GaAs interface,which effectively relieve most of the strain energy.In the temperature range from T = 26 K to 300 K,photoluminescence of the MQW is dominated by the ground state electron to ground state heavy hole（el-hhl） transition, while a high energy shoulder clearly seen at T76 K can be attributed to the ground state electron to ground state light hole（el-lhl） transition.
