Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β...Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β-Ga_(2)O_(3) MOS capacitors were fabricated with ALD deposited Al_(2)O_(3) using H_(2)O or ozone(O_(3)) as precursors. Compared with the Al_(2)O_(3) gate dielectric with H_(2)O as ALD precursor, the leakage current for the O_(3) precursor case is decreased by two orders of magnitude, while it keeps the same level at the fixed charges, interface state density, and border traps. The SIMS tests show that Al_(2)O_(3) with O_(3) as precursor contains more carbon impurities. The current transport mechanism analysis suggests that the C–H complex in Al_(2)O_(3) with O_(3) precursor serves as deep energy trap to reduce the leakage current. These results indicate that the Al_(2)O_(3)/β-Ga_(2)O_(3)MOS capacitor using the O_(3) precursor has a low leakage current and holds potential for application in β-Ga_(2)O_(3) MOSFETs.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
The volatilization kinetics of antimony trisulfide in steam atmosphere was studied with thermogravimetry at temperatures from 923 to 1123 K. A theoretical model was developed to calculate the overall rate constant and...The volatilization kinetics of antimony trisulfide in steam atmosphere was studied with thermogravimetry at temperatures from 923 to 1123 K. A theoretical model was developed to calculate the overall rate constant and the mass transfer coefficient in gas phases. The experimental results show that the volatilization rate is enhanced with increasing temperature and steam flow rate. The volatilization rate is mainly controlled by the mass transport in gas phases. The apparent activation energy for the process is found to be 59.93 kJ/mol. It is demonstrated that Sb2S3 is dominantly oxidized into Sb2O3 and H2S by water vapor in the volatilization process. Some antimony metal is formed. The reaction mechanism is discussed in accordance with experimental data.展开更多
Sb2S3 solar cells with substrate structure usually suffer from pretty low short circuit current(JSC)due to the defects and poor carrier transport.The Sb2S3,as a one-dimensional material,exhibits orientation-dependent ...Sb2S3 solar cells with substrate structure usually suffer from pretty low short circuit current(JSC)due to the defects and poor carrier transport.The Sb2S3,as a one-dimensional material,exhibits orientation-dependent carrier transport property.In this work,a thin MoSe2 layer is directly synthesized on the Mo substrate followed by depositing the Sb2S3 thin film.The x-ray diffraction(XRD)patterns confirm that a thin MoSe2 layer can improve the crystallization of the Sb2S3 film and induce(hk1)orientations,which can provide more carrier transport channels.Kelvin probe force microscopy(KPFM)results suggest that this modified Sb2S3 film has a benign surface with less defects and dangling bonds.The variation of the surface potential of Sb2S3 indicates a much more efficient carrier separation.Consequently,the power conversion efficiency(PCE)of the substrate structured Sb2S3 thin film solar cell is improved from 1.36%to 1.86%,which is the best efficiency of the substrate structured Sb2S3 thin film solar cell,and JSC significantly increases to 13.6 mA/cm^2.According to the external quantum efficiency(EQE)and C-V measurements,the modified crystallization and elevated built-in electric field are the main causes.展开更多
Sb 2 O 3 nanoparticles were prepared via hydrolyze reaction of SbCl 3 in water - ethanol solution,and were char - acterized by XRD and TEM.In addition,the effect of reactive condition on particle size was also investi...Sb 2 O 3 nanoparticles were prepared via hydrolyze reaction of SbCl 3 in water - ethanol solution,and were char - acterized by XRD and TEM.In addition,the effect of reactive condition on particle size was also investigated systematically.When the sample modified by coupling agent was applied in formulation of plastic,the mechanical property and flame retardancy was better than micron sample.展开更多
基金Project supported in part by the Science and Technology Development Plan Project of Jilin Province, China (Grant No. YDZJ202303CGZH022)the National Key Research and Development Program of China (Grant No. 2024YFE0205300)+1 种基金the National Natural Science Foundation of China (Grant No. 62471504)the Open Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-Sen University) (Grant No. OEMT-2023KF-05)。
文摘Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β-Ga_(2)O_(3) MOS capacitors were fabricated with ALD deposited Al_(2)O_(3) using H_(2)O or ozone(O_(3)) as precursors. Compared with the Al_(2)O_(3) gate dielectric with H_(2)O as ALD precursor, the leakage current for the O_(3) precursor case is decreased by two orders of magnitude, while it keeps the same level at the fixed charges, interface state density, and border traps. The SIMS tests show that Al_(2)O_(3) with O_(3) as precursor contains more carbon impurities. The current transport mechanism analysis suggests that the C–H complex in Al_(2)O_(3) with O_(3) precursor serves as deep energy trap to reduce the leakage current. These results indicate that the Al_(2)O_(3)/β-Ga_(2)O_(3)MOS capacitor using the O_(3) precursor has a low leakage current and holds potential for application in β-Ga_(2)O_(3) MOSFETs.
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This work was supported by the National Natural Science Foundation of China under grant No.59964001.
文摘The volatilization kinetics of antimony trisulfide in steam atmosphere was studied with thermogravimetry at temperatures from 923 to 1123 K. A theoretical model was developed to calculate the overall rate constant and the mass transfer coefficient in gas phases. The experimental results show that the volatilization rate is enhanced with increasing temperature and steam flow rate. The volatilization rate is mainly controlled by the mass transport in gas phases. The apparent activation energy for the process is found to be 59.93 kJ/mol. It is demonstrated that Sb2S3 is dominantly oxidized into Sb2O3 and H2S by water vapor in the volatilization process. Some antimony metal is formed. The reaction mechanism is discussed in accordance with experimental data.
基金Project supported by the National Key R&D Program of China(Grant Nos.2019YFB1503500,2018YFE0203400,and 2018YFB1500200)the National Natural Science Foundation of China(Grant No.U1902218)+1 种基金the YangFan Innovative and Entrepreneurial Research Team Project of China(Grant No.2014YT02N037)the 111 Project,China(Grant No.B16027).
文摘Sb2S3 solar cells with substrate structure usually suffer from pretty low short circuit current(JSC)due to the defects and poor carrier transport.The Sb2S3,as a one-dimensional material,exhibits orientation-dependent carrier transport property.In this work,a thin MoSe2 layer is directly synthesized on the Mo substrate followed by depositing the Sb2S3 thin film.The x-ray diffraction(XRD)patterns confirm that a thin MoSe2 layer can improve the crystallization of the Sb2S3 film and induce(hk1)orientations,which can provide more carrier transport channels.Kelvin probe force microscopy(KPFM)results suggest that this modified Sb2S3 film has a benign surface with less defects and dangling bonds.The variation of the surface potential of Sb2S3 indicates a much more efficient carrier separation.Consequently,the power conversion efficiency(PCE)of the substrate structured Sb2S3 thin film solar cell is improved from 1.36%to 1.86%,which is the best efficiency of the substrate structured Sb2S3 thin film solar cell,and JSC significantly increases to 13.6 mA/cm^2.According to the external quantum efficiency(EQE)and C-V measurements,the modified crystallization and elevated built-in electric field are the main causes.
文摘Sb 2 O 3 nanoparticles were prepared via hydrolyze reaction of SbCl 3 in water - ethanol solution,and were char - acterized by XRD and TEM.In addition,the effect of reactive condition on particle size was also investigated systematically.When the sample modified by coupling agent was applied in formulation of plastic,the mechanical property and flame retardancy was better than micron sample.
