The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon ...The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.展开更多
The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges be...The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.展开更多
为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方...为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方法,通过精确调控吸收层掺杂、势垒层掺杂、势垒层厚度、温度和组分等,构建出高能量势垒以有效阻挡多数载流子,允许少数载流子迁移,实现价带偏移(Valence Band Offset,VBO)接近于零的要求,从而有效降低暗电流。研究结果表明,在1×10^(15)~1×10^(17)cm^(-3)范围内降低势垒层掺杂浓度,VBO和暗电流开启电压绝对值均会减小,当AlAs1-xSbx势垒中Sb组分为0.91时,VBO接近于零。对于吸收层,随着掺杂浓度的提高,暗电流呈现减小趋势,但趋势较不明显。在-0.5V偏压,140 K工作条件下,吸收层和势垒层掺杂浓度分别为1×10^(13)cm^(-3),1×10^(15)cm^(-3),吸收层与势垒层厚度分别为3μm,80 nm,得到器件结构参数优化后的暗电流低至4.5×10^(-7)A/cm^(2),证明InAs/InAsSb中波红外探测器具有高温工作的应用前景,可广泛应用于导弹预警、红外制导、航空航天等领域。展开更多
InAsN nanowires on InAs stems were obtained using plasma-assisted molecular beam epitaxy on a SiOx/Si(111)sub-strate.Also,heterostructured InAs/InAsN and InAsN/InP nanowires were grown in the core/shell geometry.In th...InAsN nanowires on InAs stems were obtained using plasma-assisted molecular beam epitaxy on a SiOx/Si(111)sub-strate.Also,heterostructured InAs/InAsN and InAsN/InP nanowires were grown in the core/shell geometry.In the low-temperature photoluminescence spectra of the grown structures,spectral features are observed that correspond to the polytypic structure of nanowires with a predominance of the wurtzite phase and parasitic islands of the sphalerite phase.It was shown that the interband photoluminescence spectral features of InAsN nanowires experience a red shift relative to the pristine InAs nanowires.The incorporation of nitrogen reduces the bandgap by splitting the conduction band into two subbands.The position of the spectral features in the photoluminescence spectra confirms the formation of a nitride solid solution with a poly-typic hexagonal structure,having a concentration of nitrogen atoms of up to 0.7%.Additional passivation of the nanowire surface with InP leads to a decrease in the intensity of nonradiative recombination and an improvement in the photoluminescent response of the nanowires,which makes it possible to detect photoluminescence emission at room temperature.Thus,by changing the composition and morphology of nanowires,it is possible to control their electronic structure,which allows varying the operating range of detectors and mid-IR radiation sources based on them.展开更多
In this paper,a planar junction mid-wavelength infrared(MWIR)photodetector based on an InAs/GaSb type-Ⅱsuper-lattices(T2SLs)is reported.The Intrinsic-πMN superlattices was grown by the molecular beam epitaxy(MBE),fo...In this paper,a planar junction mid-wavelength infrared(MWIR)photodetector based on an InAs/GaSb type-Ⅱsuper-lattices(T2SLs)is reported.The Intrinsic-πMN superlattices was grown by the molecular beam epitaxy(MBE),followed with a ZnS layer grown by the chemical vapor deposition(CVD).The p-type contact layer was constructed by thermal diffusion in the undoped superlattices.The Zinc atom was successfully realised into the superlattice and a PπMN T2SL structure was con-structed.Furthermore,the effects of different diffusion temperatures on the dark current performance of the devices were researched.The 50%cut-off wavelength of the photodetector is 5.26μm at 77 K with 0 V bias.The minimum dark current density is 8.67×10^(−5) A/cm^(2) and the maximum quantum efficiency of 42.5%,and the maximum detectivity reaches 3.90×10^(10) cm·Hz^(1/2)/W at 77 K.The 640×512 focal plane arrays(FPA)based on the planner junction were fabricated afterwards.The FPA achieves a noise equivalent temperature difference(NETD)of 539 mK.展开更多
报道了320×256元InAs/GaSb II类超晶格红外双色焦平面阵列探测器的初步结果.探测器采用PN-NP叠层双色外延结构,信号提取采用顺序读出方式.运用分子束外延技术在GaSb衬底上生长超晶格材料,双波段红外吸收区的超晶格周期结构分别为7 ...报道了320×256元InAs/GaSb II类超晶格红外双色焦平面阵列探测器的初步结果.探测器采用PN-NP叠层双色外延结构,信号提取采用顺序读出方式.运用分子束外延技术在GaSb衬底上生长超晶格材料,双波段红外吸收区的超晶格周期结构分别为7 ML InAs/7 ML GaSb和10 ML InAs/10 ML GaSb.焦平面阵列像元中心距为30μm.在77 K时测试,器件双色波段的50%响应截止波长分别为4.2μm和5.5μm,其中N-on-P器件平均峰值探测率达到6.0×10^(10) cmHz^(1/2)W^(-1),盲元率为8.6%;P-on-N器件平均峰值探测率达到2.3×10~9 cmHz^(1/2)W^(-1),盲元率为9.8%.红外焦平面偏压调节成像测试得到较为清晰的双波段成像.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12494604,12393834,12393831,62274014,6223501662335015)the National Key R&D Program of China (Grant No.2024YFA1208900)。
文摘The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos.XDB28000000 and XDB0460000)the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2021ZD0302600)the National Key Research and Development Program of China(Grant No.2024YFA1409002)。
文摘The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
文摘为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方法,通过精确调控吸收层掺杂、势垒层掺杂、势垒层厚度、温度和组分等,构建出高能量势垒以有效阻挡多数载流子,允许少数载流子迁移,实现价带偏移(Valence Band Offset,VBO)接近于零的要求,从而有效降低暗电流。研究结果表明,在1×10^(15)~1×10^(17)cm^(-3)范围内降低势垒层掺杂浓度,VBO和暗电流开启电压绝对值均会减小,当AlAs1-xSbx势垒中Sb组分为0.91时,VBO接近于零。对于吸收层,随着掺杂浓度的提高,暗电流呈现减小趋势,但趋势较不明显。在-0.5V偏压,140 K工作条件下,吸收层和势垒层掺杂浓度分别为1×10^(13)cm^(-3),1×10^(15)cm^(-3),吸收层与势垒层厚度分别为3μm,80 nm,得到器件结构参数优化后的暗电流低至4.5×10^(-7)A/cm^(2),证明InAs/InAsSb中波红外探测器具有高温工作的应用前景,可广泛应用于导弹预警、红外制导、航空航天等领域。
基金the Ministry of Education and Science of the Russian Federation (state assignment No. FSEG-2023-0016) for financial support of optical studiesfinancially supported by FSRM 2023-0007 project provided by the Ministry of Education and Science of the Russian Federation.
文摘InAsN nanowires on InAs stems were obtained using plasma-assisted molecular beam epitaxy on a SiOx/Si(111)sub-strate.Also,heterostructured InAs/InAsN and InAsN/InP nanowires were grown in the core/shell geometry.In the low-temperature photoluminescence spectra of the grown structures,spectral features are observed that correspond to the polytypic structure of nanowires with a predominance of the wurtzite phase and parasitic islands of the sphalerite phase.It was shown that the interband photoluminescence spectral features of InAsN nanowires experience a red shift relative to the pristine InAs nanowires.The incorporation of nitrogen reduces the bandgap by splitting the conduction band into two subbands.The position of the spectral features in the photoluminescence spectra confirms the formation of a nitride solid solution with a poly-typic hexagonal structure,having a concentration of nitrogen atoms of up to 0.7%.Additional passivation of the nanowire surface with InP leads to a decrease in the intensity of nonradiative recombination and an improvement in the photoluminescent response of the nanowires,which makes it possible to detect photoluminescence emission at room temperature.Thus,by changing the composition and morphology of nanowires,it is possible to control their electronic structure,which allows varying the operating range of detectors and mid-IR radiation sources based on them.
基金supported by the National Key Technologies R&D Program of China(Grant Nos.2024YFA1208904,2019YFA0705203)Major Program of the National Natural Science Foundation of China(Grant Nos.62004189,61274013)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0460000)the Research Foundation for Advanced Talents of the Chinese Academy of Sciences(Grant No.E27RBB03).
文摘In this paper,a planar junction mid-wavelength infrared(MWIR)photodetector based on an InAs/GaSb type-Ⅱsuper-lattices(T2SLs)is reported.The Intrinsic-πMN superlattices was grown by the molecular beam epitaxy(MBE),followed with a ZnS layer grown by the chemical vapor deposition(CVD).The p-type contact layer was constructed by thermal diffusion in the undoped superlattices.The Zinc atom was successfully realised into the superlattice and a PπMN T2SL structure was con-structed.Furthermore,the effects of different diffusion temperatures on the dark current performance of the devices were researched.The 50%cut-off wavelength of the photodetector is 5.26μm at 77 K with 0 V bias.The minimum dark current density is 8.67×10^(−5) A/cm^(2) and the maximum quantum efficiency of 42.5%,and the maximum detectivity reaches 3.90×10^(10) cm·Hz^(1/2)/W at 77 K.The 640×512 focal plane arrays(FPA)based on the planner junction were fabricated afterwards.The FPA achieves a noise equivalent temperature difference(NETD)of 539 mK.
文摘报道了320×256元InAs/GaSb II类超晶格红外双色焦平面阵列探测器的初步结果.探测器采用PN-NP叠层双色外延结构,信号提取采用顺序读出方式.运用分子束外延技术在GaSb衬底上生长超晶格材料,双波段红外吸收区的超晶格周期结构分别为7 ML InAs/7 ML GaSb和10 ML InAs/10 ML GaSb.焦平面阵列像元中心距为30μm.在77 K时测试,器件双色波段的50%响应截止波长分别为4.2μm和5.5μm,其中N-on-P器件平均峰值探测率达到6.0×10^(10) cmHz^(1/2)W^(-1),盲元率为8.6%;P-on-N器件平均峰值探测率达到2.3×10~9 cmHz^(1/2)W^(-1),盲元率为9.8%.红外焦平面偏压调节成像测试得到较为清晰的双波段成像.
