为了研究不同制备工艺对电极欧姆接触特性的影响,分别采用真空蒸发法、溅射法及化学沉积法在CdZnTe晶片表面制备了Au薄膜电极,通过测试样品的SEM、I-V曲线及交流阻抗谱,研究了不同电极制备工艺及退火处理对Au薄膜电极的微观结构及欧姆...为了研究不同制备工艺对电极欧姆接触特性的影响,分别采用真空蒸发法、溅射法及化学沉积法在CdZnTe晶片表面制备了Au薄膜电极,通过测试样品的SEM、I-V曲线及交流阻抗谱,研究了不同电极制备工艺及退火处理对Au薄膜电极的微观结构及欧姆接触特性的影响。结果表明化学沉积法制备的Au薄膜表面更加平整、致密,接触势垒的高度较低,电极欧姆接触特性最好。退火处理可以改善电极的欧姆接触特性,100℃退火后,化学沉积法制备的Au电极的欧姆系数由0.883提高至0.915,势垒高度由0.492降低至0.487 e V。交流阻抗谱分析表明,化学沉积法制备电极具有最低的接触势垒,这与界面处晶片表面的掺杂及缺陷的变化有关。展开更多
The response wavelength of the blocked-impurity-band(BIB)structured infrared detector can reach 200µm,which is the most important very long wavelength infrared astronomical detector.The ion implantation method gr...The response wavelength of the blocked-impurity-band(BIB)structured infrared detector can reach 200µm,which is the most important very long wavelength infrared astronomical detector.The ion implantation method greatly simplifies the fabrication process of the device,but it is easy to cause lattice damage,introduce crystalline defects,and lead to the increase of the dark current of detectors.Herein,the boron-doped germanium ion implantation process was studied,and the involved lattice damage mechanism was discussed.Experimental conditions involved using 80 keV energy for boron ion implantation,with doses ranging from 1×10^(13)cm^(-2)to 3×10^(15)cm^(-2).After implantation,thermal annealing at 450℃was implemented to optimize dopant activation and mitigate the effects of ion implantation.Various sophisticated characterization techniques,including X-ray dif⁃fraction(XRD),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and secondary ion mass spec⁃trometry(SIMS)were used to clarify lattice damage.At lower doses,no notable structural alterations were ob⁃served.However,as the dosage increased,specific micro distortions became apparent,which could be attributed to point defects and residual strain.The created lattice damage was recovered by thermal treatment,however,an irreversible strain induced by implantation still existed at heavily dosed samples.展开更多
InAs infrared-sensitive solar cells are fabricated by using the films grown by the liquid phase epitaxy technique. The film microstructures are characterized by x-ray diffraction and scanning electronic microscopy. Th...InAs infrared-sensitive solar cells are fabricated by using the films grown by the liquid phase epitaxy technique. The film microstructures are characterized by x-ray diffraction and scanning electronic microscopy. The current-voltage characteristics of the solar cells in the dark and under AM1.5 illumination at 300 K and 77 K are discussed. The conversion efficiency of p-InAs/n-sub InAs cells decreases when the thickness of the p-type film changes from 1.7 μm to 3.5 μm, which is caused by the reduced effective photons near p？n junction. The p-InAs/n-InAs/n-sub InAs solar cell with the conversion efficiency of 7.43% in 1-2.5 μm under AM1.5 at 77 K is obtained. The short circuit current density increases dramatically with decreasing temperature due to the weakened effect of phonon scattering.展开更多
The structural and electronic properties of sodium bromide （NaBr） are investigated by the density functional theory （DFT） within the generalized gradient approximation （GGA） for the exchange and correlation ener...The structural and electronic properties of sodium bromide （NaBr） are investigated by the density functional theory （DFT） within the generalized gradient approximation （GGA） for the exchange and correlation energy. The equilibrium lattice constant, bulk modulus and its pressure derivative are obtained by fitting the calculated total energy to the third-order Birch-Murnaghan equation of state. The band structure along the higher symmetry axes in the Brillouin zone, the density of states （DOS） and the partial density of states （PDOS） are presented. The results have been discussed and compared with the available experimental and theoretical data.展开更多
Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flex...Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices, while it is a very challenging work, and usually amorphous, polycrystalline or discontinuous single crystalline films are achieved. Here we demonstrate the direct growth of high-quality Bi2 Te3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique. Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film, although amounts of disoriented crystallites are generated due to fast growth rate. By inserting a quartz filter into the growth tube, the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction. Furthermore, flexible Bi2 Te3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending, which also confirms the obtained fexible films suitable for electronic applications.展开更多
PbZrxTi1-xO3(PZT)fims are fabricated on F-doped tin oxide(FTO)substrates using chemical solutions containing PVP polymer and rapid thermal annealing processing.The dependence of the layered PZT multilayer formation an...PbZrxTi1-xO3(PZT)fims are fabricated on F-doped tin oxide(FTO)substrates using chemical solutions containing PVP polymer and rapid thermal annealing processing.The dependence of the layered PZT multilayer formation and their optical properties on the Zr content x are examined.It is found that all the PZT films are crystallized and exhibit 110-preferred orientation.When x varies in the region of 0-0.8,the PZT films display lamellar structures,and a high reflection band occurs in each optical reflectance spectrum curve.Especially,those PZT fikms with Zr/Ti atomic ratio of 35/65-65/35 show clearly layered cross-sectional morphologies arranged alternatively by porous and dense PZT layers,and have a peak optical reflectivity of>70%and a band width of>45 nm.To obtain the optimal Bragg reflection performance of the PZT multilayers,the Zr content should be selected in the range of 0.35-0.65.展开更多
Bi_(2)Te_(3)films are grown on(111)-oriented GaAs substrates by using the hot wall epitaxy method and the surface oxidation properties in the films are investigated by x-ray photoelectron spectroscopy,Raman spectrosco...Bi_(2)Te_(3)films are grown on(111)-oriented GaAs substrates by using the hot wall epitaxy method and the surface oxidation properties in the films are investigated by x-ray photoelectron spectroscopy,Raman spectroscopy,and x-ray diffraction.The results show that the films are c-axis oriented.Two pairs of new peaks in the XPS spectra involved with the binding energies from Bi 4f and Te 3d electrons correspond to Bi–O–Te bonds.Besides the A^(1)_(1)g,E^(2)g and A^(2)_(1)g vibration modes from Bi_(2)Te_(3)films,two new peaks at 93.5 cm^(-1)and 123 cm^(-1)are observed in Raman spectra,which are assigned toα-Bi2O_(3)and TeO_(2),respectively.Our results are helpful for analyzing the degradation mechanism of topological surface states in Bi_(2)Te_(3).展开更多
基金Supported by National Natural Science Foundation of China(11933006)the Frontier Science Research Project(Key Programs)of the Chinese Academy of Sciences(QYZDJ-SSW-SLH018)。
文摘为了研究不同制备工艺对电极欧姆接触特性的影响,分别采用真空蒸发法、溅射法及化学沉积法在CdZnTe晶片表面制备了Au薄膜电极,通过测试样品的SEM、I-V曲线及交流阻抗谱,研究了不同电极制备工艺及退火处理对Au薄膜电极的微观结构及欧姆接触特性的影响。结果表明化学沉积法制备的Au薄膜表面更加平整、致密,接触势垒的高度较低,电极欧姆接触特性最好。退火处理可以改善电极的欧姆接触特性,100℃退火后,化学沉积法制备的Au电极的欧姆系数由0.883提高至0.915,势垒高度由0.492降低至0.487 e V。交流阻抗谱分析表明,化学沉积法制备电极具有最低的接触势垒,这与界面处晶片表面的掺杂及缺陷的变化有关。
基金Supported by National Key R&D Program of China(2023YFA1608701)National Natural Science Foundation of China(62274168,11933006,U2141240)Hangzhou Leading Innovation and Entrepreneurship Team(TD2020002)。
文摘The response wavelength of the blocked-impurity-band(BIB)structured infrared detector can reach 200µm,which is the most important very long wavelength infrared astronomical detector.The ion implantation method greatly simplifies the fabrication process of the device,but it is easy to cause lattice damage,introduce crystalline defects,and lead to the increase of the dark current of detectors.Herein,the boron-doped germanium ion implantation process was studied,and the involved lattice damage mechanism was discussed.Experimental conditions involved using 80 keV energy for boron ion implantation,with doses ranging from 1×10^(13)cm^(-2)to 3×10^(15)cm^(-2).After implantation,thermal annealing at 450℃was implemented to optimize dopant activation and mitigate the effects of ion implantation.Various sophisticated characterization techniques,including X-ray dif⁃fraction(XRD),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and secondary ion mass spec⁃trometry(SIMS)were used to clarify lattice damage.At lower doses,no notable structural alterations were ob⁃served.However,as the dosage increased,specific micro distortions became apparent,which could be attributed to point defects and residual strain.The created lattice damage was recovered by thermal treatment,however,an irreversible strain induced by implantation still existed at heavily dosed samples.
基金Supported by the National Basic Research Program of China under Grant No 2010CB933700, the National Natural Science Foundation of China under Grant Nos 10804117 and 60221502, the Natural Science Foundation of Shanghai under Grant No 08ZR1421900, and the Knowledge Innovation Project in Chinese Academy of Sciences.
文摘InAs infrared-sensitive solar cells are fabricated by using the films grown by the liquid phase epitaxy technique. The film microstructures are characterized by x-ray diffraction and scanning electronic microscopy. The current-voltage characteristics of the solar cells in the dark and under AM1.5 illumination at 300 K and 77 K are discussed. The conversion efficiency of p-InAs/n-sub InAs cells decreases when the thickness of the p-type film changes from 1.7 μm to 3.5 μm, which is caused by the reduced effective photons near p？n junction. The p-InAs/n-InAs/n-sub InAs solar cell with the conversion efficiency of 7.43% in 1-2.5 μm under AM1.5 at 77 K is obtained. The short circuit current density increases dramatically with decreasing temperature due to the weakened effect of phonon scattering.
文摘The structural and electronic properties of sodium bromide （NaBr） are investigated by the density functional theory （DFT） within the generalized gradient approximation （GGA） for the exchange and correlation energy. The equilibrium lattice constant, bulk modulus and its pressure derivative are obtained by fitting the calculated total energy to the third-order Birch-Murnaghan equation of state. The band structure along the higher symmetry axes in the Brillouin zone, the density of states （DOS） and the partial density of states （PDOS） are presented. The results have been discussed and compared with the available experimental and theoretical data.
基金Supported by the National Basic Research Program of China under Grant No 2012CB619200the National Natural Science Foundation of China under Grant Nos 61290304,11074265 and 11174307+1 种基金the Natural Science Foundation of Shanghai under Grant No 16ZR1441200the Frontier Science Research Project(Key Programs)of Chinese Academy of Sciences under Grant No QYZDJ-SSW-SLH018
文摘Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices, while it is a very challenging work, and usually amorphous, polycrystalline or discontinuous single crystalline films are achieved. Here we demonstrate the direct growth of high-quality Bi2 Te3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique. Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film, although amounts of disoriented crystallites are generated due to fast growth rate. By inserting a quartz filter into the growth tube, the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction. Furthermore, flexible Bi2 Te3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending, which also confirms the obtained fexible films suitable for electronic applications.
基金the Frontier Science Research Project of Chinese Academy of Sciences(No.QYZDJ-SSW-SLH018)the National Natural Science Foundation of China(Nos.11174307 and 11933006)the National Key Basic Research Program of China(No.2016YFB0402405).
文摘PbZrxTi1-xO3(PZT)fims are fabricated on F-doped tin oxide(FTO)substrates using chemical solutions containing PVP polymer and rapid thermal annealing processing.The dependence of the layered PZT multilayer formation and their optical properties on the Zr content x are examined.It is found that all the PZT films are crystallized and exhibit 110-preferred orientation.When x varies in the region of 0-0.8,the PZT films display lamellar structures,and a high reflection band occurs in each optical reflectance spectrum curve.Especially,those PZT fikms with Zr/Ti atomic ratio of 35/65-65/35 show clearly layered cross-sectional morphologies arranged alternatively by porous and dense PZT layers,and have a peak optical reflectivity of>70%and a band width of>45 nm.To obtain the optimal Bragg reflection performance of the PZT multilayers,the Zr content should be selected in the range of 0.35-0.65.
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB934300 and 2012CB619200the National Natural Science Foundation of China under Grant Nos 61290304,11074265 and 11174307the Natural Science Foundation of Shanghai(12ZR1435500).
文摘Bi_(2)Te_(3)films are grown on(111)-oriented GaAs substrates by using the hot wall epitaxy method and the surface oxidation properties in the films are investigated by x-ray photoelectron spectroscopy,Raman spectroscopy,and x-ray diffraction.The results show that the films are c-axis oriented.Two pairs of new peaks in the XPS spectra involved with the binding energies from Bi 4f and Te 3d electrons correspond to Bi–O–Te bonds.Besides the A^(1)_(1)g,E^(2)g and A^(2)_(1)g vibration modes from Bi_(2)Te_(3)films,two new peaks at 93.5 cm^(-1)and 123 cm^(-1)are observed in Raman spectra,which are assigned toα-Bi2O_(3)and TeO_(2),respectively.Our results are helpful for analyzing the degradation mechanism of topological surface states in Bi_(2)Te_(3).
