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
采用分子束外延技术在GaSb衬底上生长了PIN型长波红外28 ML InAs/7 ML InAs0.48Sb0.52超晶格探测器材料,研究了Sb浸润界面对其表面形貌、晶体结构和光电性能的影响。结果发现:相对于无界面控制的超晶格,采用Sb浸润界面的超晶格表面更平...采用分子束外延技术在GaSb衬底上生长了PIN型长波红外28 ML InAs/7 ML InAs0.48Sb0.52超晶格探测器材料,研究了Sb浸润界面对其表面形貌、晶体结构和光电性能的影响。结果发现:相对于无界面控制的超晶格,采用Sb浸润界面的超晶格表面更平整,表面粗糙度仅为1.28;超晶格晶体结构更完整,界面起伏明显减小,与衬底的晶格失配度由3.26%减小到2.97%。InAs/InAsSb超晶格探测器的50%截止波长为10μm,量子效率为3.1%;Sb浸润界面的超晶格具有更低的暗电流和更高的微分阻抗,-50 mV偏压下暗电流密度为0.12 A/cm^ 2,零偏阻抗面积乘积(R 0A)为0.44Ω·cm^2,计算得到探测率为5.06×10^7 cm·Hz 1/2/W。Sb浸润界面有效抑制了Sb的扩散,提高了超晶格的晶体质量和探测性能,但失配应力依然很大。这些结果为高质量长波红外InAs/InAsSb超晶格的界面生长提供了依据。展开更多
Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional ...Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional monolayer alloy method was used to grow InAsSb alloy with better controlled alloy composition. The as-grown T2SL gave eleven satellite peaks and a first satellite peak with a narrow full-width-half-maximum (FWHM) of 20.5arcsec (1 arcsec=0.01592°). Strain mapping results indicated limited Sb diffusion through the As-Sb exchange process at the interface. Moreover, unlike interface states caused by the As-Sb exchange effect, this relatively clear interface was distinctive with localized states with higher activation energies of the non-radiative recombination process ((18±1) meV and (84±12) meV at different temperature ranges), which means that this interface state introduced by fractional monolayer alloy growth method can effectively suppress Auger recombination process in T2SL. Through this interface engineering of InAs/InAsSb Type-Ⅱ superlattice, it achieved detective photoluminescence (PL) signal with the center wavelength of 9μm at 250K.展开更多
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
In this paper,we demonstrate nBn InAs/InAsSb type II superlattice(T2SL)photodetectors with AlAsSb as the barrier that targets mid-wavelength infrared(MWIR)detection.To improve operating temperature and suppress dark c...In this paper,we demonstrate nBn InAs/InAsSb type II superlattice(T2SL)photodetectors with AlAsSb as the barrier that targets mid-wavelength infrared(MWIR)detection.To improve operating temperature and suppress dark current,a specific Sb soaking technique was employed to improve the interface abruptness of the superlattice with device passivation using a SiO_(2) layer.These result in ultralow dark current density of 6.28×10^(-6)A/cm^(2)and 0.31 A/cm^(2)under-600 mV at 97 K and297 K,respectively,which is lower than most reported InAs/InAsSb-based MWIR photodetectors.Corresponding resistance area product values of 3.20×10^(4)Ω·cm^(2)and 1.32Ω·cm^(2)were obtained at 97 K and 297 K.A peak responsivity of 0.39 A/W with a cutoff wavelength around 5.5μm and a peak detectivity of 2.1×10^(9)cm·Hz^(1/2)/W were obtained at a high operating temperature up to 237 K.展开更多
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Supported by the National Natural Science Foundation of China(61774130,11474248,61790581,51973070)the Ph.D.Pro⁃grams Foundation of Ministry of Education of China(20105303120002)National Key Technology Research and Development Program of the Ministry of Sci⁃ence and Technology of China(2018YFA0209101).
基金financially supported by the National Natural Science Foundation of China (Nos. 62074018 and 61704011)the China Postdoctoral Science Foundation Funded Project (Nos. 2019M652176 and 2019M661680)+4 种基金the Developing Project of Science and Technology of Jilin Province (Nos. 20200301052RQ, 20200201266JC, 20190701029GH, 20180519017JH and 20180520177JH)the Project of Education Department of Jilin Province (No. JJKH20210831KJ)the Natural Science Foundation of Guangdong Province (No. 2020A1515010868)Shenzhen Fundamental Research Fund (No. JCYJ20180307151538972)supported by R&D project of Collighter Co., Ltd。
文摘Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional monolayer alloy method was used to grow InAsSb alloy with better controlled alloy composition. The as-grown T2SL gave eleven satellite peaks and a first satellite peak with a narrow full-width-half-maximum (FWHM) of 20.5arcsec (1 arcsec=0.01592°). Strain mapping results indicated limited Sb diffusion through the As-Sb exchange process at the interface. Moreover, unlike interface states caused by the As-Sb exchange effect, this relatively clear interface was distinctive with localized states with higher activation energies of the non-radiative recombination process ((18±1) meV and (84±12) meV at different temperature ranges), which means that this interface state introduced by fractional monolayer alloy growth method can effectively suppress Auger recombination process in T2SL. Through this interface engineering of InAs/InAsSb Type-Ⅱ superlattice, it achieved detective photoluminescence (PL) signal with the center wavelength of 9μm at 250K.
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.
基金supported by the National Science and Technology Major Project(No.2018YFE0200900)。
文摘In this paper,we demonstrate nBn InAs/InAsSb type II superlattice(T2SL)photodetectors with AlAsSb as the barrier that targets mid-wavelength infrared(MWIR)detection.To improve operating temperature and suppress dark current,a specific Sb soaking technique was employed to improve the interface abruptness of the superlattice with device passivation using a SiO_(2) layer.These result in ultralow dark current density of 6.28×10^(-6)A/cm^(2)and 0.31 A/cm^(2)under-600 mV at 97 K and297 K,respectively,which is lower than most reported InAs/InAsSb-based MWIR photodetectors.Corresponding resistance area product values of 3.20×10^(4)Ω·cm^(2)and 1.32Ω·cm^(2)were obtained at 97 K and 297 K.A peak responsivity of 0.39 A/W with a cutoff wavelength around 5.5μm and a peak detectivity of 2.1×10^(9)cm·Hz^(1/2)/W were obtained at a high operating temperature up to 237 K.
