Te-doped GaSb single crystals are studied by measuring Hall effect, infrared （IR） transmission and photoluminescence （PL） spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as ...Te-doped GaSb single crystals are studied by measuring Hall effect, infrared （IR） transmission and photoluminescence （PL） spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as 60% by the critical control of the Te-doping concentration and electrical compensation. The concentration of the native acceptor-associated defects is apparently low in the Te-doped GaSb compared with those in undoped and heavily Te-doped GaSb. The mechanism for the high IR transmittance is analyzed by considering the defect-involved optical absorption process.展开更多
In this work the influence of aqueous sulfur passivation on the surface of n-type (100) GaSb single crystals has been studied through low-temperature photoluminescence (PL) characterization. The samples were passivate...In this work the influence of aqueous sulfur passivation on the surface of n-type (100) GaSb single crystals has been studied through low-temperature photoluminescence (PL) characterization. The samples were passivated at different times using aqueous solutions of sodium sulfide. PL spectroscopy was used to determinate the optimum time of sulfur passivation, through the measurement of the PL intensity for the different passivation times. For the samples measured, the PL spectra show the presence of two emission bands, whose intensity and energy position change for the different passivation times of the GaSb samples. According to the PL results, a passivation surface treatment of 6 min shows the highest PL intensity spectrum.展开更多
Violet phosphorus,a recently explored layered elemental semiconductor,has attracted much attention due to its unique photoelectric,mechanical properties,and high hole mobility.Herein,violet arsenic phosphorus has for ...Violet phosphorus,a recently explored layered elemental semiconductor,has attracted much attention due to its unique photoelectric,mechanical properties,and high hole mobility.Herein,violet arsenic phosphorus has for the first time been synthesized by a molten lead method.The crystal structure of violet arsenic phosphorus(P^(83.4)As_(0.6),CSD-2408761)was determined by single crystal X-ray diffraction to have similar structure as that of violet phosphorus,where P12 is occupied by arsenic/phosphorus(As/P)atoms as mixed occupancy sites As1/P12.The arsenic substitution has been demonstrated to tune the band structure of violet phosphorus,switching p-type of violet phosphorus to high-performance n-type violet arsenic phosphorus.The effective electron mass along the<010>direction is significantly reduced from 1.792 to 0.515 m_(0)by arsenic substitution,resulting in an extremely high electron mobility of 2622.503 cm^(2)V^(-1)s^(-1).The field effect transistor built with P_(83.4)As_(0.6)nanosheets was measured to have a high electron mobility(137.06 cm^(2)V^(-1)s^(-1),61.2 nm),even under ambient conditions for 5 h,much higher than the hole mobility of violet phosphorene nanosheets(4.07 cm^(2)V^(-1)s^(-1),73.3 nm).This work provides a new idea for designing phosphorus-based materials for field effect transistors,giving significant potential in complementary metal-oxide-semiconductor applications.展开更多
The relatively lower performance of n-type legs has significantly hindered the application of PbTe ma-terials in medium-temperature thermoelectric(TE)power generation,underscoring the urgent need to enhance the TE per...The relatively lower performance of n-type legs has significantly hindered the application of PbTe ma-terials in medium-temperature thermoelectric(TE)power generation,underscoring the urgent need to enhance the TE performance of n-type PbTe.In this study,electron-phonon decoupling was achieved through the precise manipulation of a single copper-doping element in PbTe(i.e.,Pb_(1.005-x)Cu_(2 x+0.003)Te),enabling the concurrent optimization of phonon transport and electrical properties.High-content Cu dop-ing induced substantial lattice strain and abundant precipitates,which effectively scattered heat-carrying phonons and significantly reduced lattice thermal conductivity.Simultaneously,the retention of high mo-bility and the self-regulation of electron concentration improved electrical performance across a broad temperature range.As a result,an impressive average zT of 1.3 was achieved from 523 to 823 K in n-type Pb_(0.985)Cu_(0.043)Te.Building on this,a seven-pair TE module was fabricated,attaining an energy conversion efficiency of∼8%under a temperature difference of 420 K.This work provides fresh insights into strate-gies for enhancing the TE performance of n-type PbTe.展开更多
Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-t...Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-type organic thermoelectric materials and wearable p/n junction thermoelectric devices remains challenging.In this work,two insulated polyamides(PA6 and PA66)that have been widely used as fiber materials are employed as novel dopants for converting p-type single-walled carbon nanotubes(SWCNTs)to n-type thermoelectric materials.Because of the electron transferability of the amide group,polyamide-doped SWCNTs exhibit excellent thermopower values as large as-56.0μV K^(-1) for PA66,and-54.5μV K^(-1) for PA6.Thermoelectric devices with five p/n junctions connected in series are fabricated.The testing device produces a thermoelectric voltage of 43.1 mV and generates 1.85μW thermoelectric power under temperature gradients of approximately 80 K.Furthermore,they display charming capability for temperature recognition and monitoring human activities as sensors.These promising results suggest that the flexible polyamide-doped SWCNT composites herein have high application potential as wearable thermoelectric electronics.展开更多
Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomer...Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.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
With high surface-to-volume ratio,the abundant surface states and high carrier concentration are challenging the nearinfrared photodetection behaviors of narrow band gap semiconductors nanowires.In this study,the narr...With high surface-to-volume ratio,the abundant surface states and high carrier concentration are challenging the nearinfrared photodetection behaviors of narrow band gap semiconductors nanowires.In this study,the narrow band gap semiconductor of Bi_(2)O_(2)Se nanosheets(NSs)is adopted to construct mixed-dimensional heterojunctions with GaSb nanowires(NWs)for demonstrating the impressive self-powered NIR photodetection.Benefiting from the built-in electric field of~140 meV,the as-constructed NW/NS mixeddimensional heterojunction self-powered photodetector shows the low dark current of 0.07 pA,high I_(light)/I_(dark)ratio of 82 and fast response times of<2/2 ms at room temperature.The self-powered photodetector performance can be further enhanced by fabricating the NW array/NS mixed-dimensional heterojunction by using a contact printing technique.The excellent photodetection performance promises the asconstructed NW/NS mixed-dimensional heterojunction self-powered photodetector in imaging and photocommunication.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.61474104 and 61504131)
文摘Te-doped GaSb single crystals are studied by measuring Hall effect, infrared （IR） transmission and photoluminescence （PL） spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as 60% by the critical control of the Te-doping concentration and electrical compensation. The concentration of the native acceptor-associated defects is apparently low in the Te-doped GaSb compared with those in undoped and heavily Te-doped GaSb. The mechanism for the high IR transmittance is analyzed by considering the defect-involved optical absorption process.
基金partially supported by the ICyTDF and CONACYT,México
文摘In this work the influence of aqueous sulfur passivation on the surface of n-type (100) GaSb single crystals has been studied through low-temperature photoluminescence (PL) characterization. The samples were passivated at different times using aqueous solutions of sodium sulfide. PL spectroscopy was used to determinate the optimum time of sulfur passivation, through the measurement of the PL intensity for the different passivation times. For the samples measured, the PL spectra show the presence of two emission bands, whose intensity and energy position change for the different passivation times of the GaSb samples. According to the PL results, a passivation surface treatment of 6 min shows the highest PL intensity spectrum.
基金supported by the National Natural Science Foundation of China(Grant No.22175136)the State Key Laboratory of Electrical Insulation and Power Equipment(Grant No.EIPE23127)the Fundamental Research Funds for the Central Universities(xtr052024009,xtr052025002).
文摘Violet phosphorus,a recently explored layered elemental semiconductor,has attracted much attention due to its unique photoelectric,mechanical properties,and high hole mobility.Herein,violet arsenic phosphorus has for the first time been synthesized by a molten lead method.The crystal structure of violet arsenic phosphorus(P^(83.4)As_(0.6),CSD-2408761)was determined by single crystal X-ray diffraction to have similar structure as that of violet phosphorus,where P12 is occupied by arsenic/phosphorus(As/P)atoms as mixed occupancy sites As1/P12.The arsenic substitution has been demonstrated to tune the band structure of violet phosphorus,switching p-type of violet phosphorus to high-performance n-type violet arsenic phosphorus.The effective electron mass along the<010>direction is significantly reduced from 1.792 to 0.515 m_(0)by arsenic substitution,resulting in an extremely high electron mobility of 2622.503 cm^(2)V^(-1)s^(-1).The field effect transistor built with P_(83.4)As_(0.6)nanosheets was measured to have a high electron mobility(137.06 cm^(2)V^(-1)s^(-1),61.2 nm),even under ambient conditions for 5 h,much higher than the hole mobility of violet phosphorene nanosheets(4.07 cm^(2)V^(-1)s^(-1),73.3 nm).This work provides a new idea for designing phosphorus-based materials for field effect transistors,giving significant potential in complementary metal-oxide-semiconductor applications.
基金support from the Regional Innovation Cooperation Project of the Sichuan Science and Technology Program(No.2024YFHZ0204)the National Key Research and Development Program of China(No.2022YFB3803900)the Innovation Research Program of Sichuan University(No.2020SCUNL112).
文摘The relatively lower performance of n-type legs has significantly hindered the application of PbTe ma-terials in medium-temperature thermoelectric(TE)power generation,underscoring the urgent need to enhance the TE performance of n-type PbTe.In this study,electron-phonon decoupling was achieved through the precise manipulation of a single copper-doping element in PbTe(i.e.,Pb_(1.005-x)Cu_(2 x+0.003)Te),enabling the concurrent optimization of phonon transport and electrical properties.High-content Cu dop-ing induced substantial lattice strain and abundant precipitates,which effectively scattered heat-carrying phonons and significantly reduced lattice thermal conductivity.Simultaneously,the retention of high mo-bility and the self-regulation of electron concentration improved electrical performance across a broad temperature range.As a result,an impressive average zT of 1.3 was achieved from 523 to 823 K in n-type Pb_(0.985)Cu_(0.043)Te.Building on this,a seven-pair TE module was fabricated,attaining an energy conversion efficiency of∼8%under a temperature difference of 420 K.This work provides fresh insights into strate-gies for enhancing the TE performance of n-type PbTe.
基金supported by the National Natural Science Foundation of China(Project no.51973120)the Natural Science Foun-dation of Guangdong Province(No.2019A1515010613)+1 种基金the Shenzhen Science and Technology Research Grant(Nos.JCYJ20170818093417096 and JCYJ20180305125649693)the Shenzhen Science and Technology Program(No.20220809111527001).
文摘Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-type organic thermoelectric materials and wearable p/n junction thermoelectric devices remains challenging.In this work,two insulated polyamides(PA6 and PA66)that have been widely used as fiber materials are employed as novel dopants for converting p-type single-walled carbon nanotubes(SWCNTs)to n-type thermoelectric materials.Because of the electron transferability of the amide group,polyamide-doped SWCNTs exhibit excellent thermopower values as large as-56.0μV K^(-1) for PA66,and-54.5μV K^(-1) for PA6.Thermoelectric devices with five p/n junctions connected in series are fabricated.The testing device produces a thermoelectric voltage of 43.1 mV and generates 1.85μW thermoelectric power under temperature gradients of approximately 80 K.Furthermore,they display charming capability for temperature recognition and monitoring human activities as sensors.These promising results suggest that the flexible polyamide-doped SWCNT composites herein have high application potential as wearable thermoelectric electronics.
基金support from the National Natural Science Foundation of China(Nos.22071007,22020102001,22335002)the National Key R&D Program of China(No.2022YFB3602802)+3 种基金Beijing Natural Science Foundation(No.Z220025)the National Facility for Protein Science in Shanghai,Shanghai Advanced Research Institute,CAS,for providing technical support in X-ray diffraction data collectionthe High-Performance Computing Platform of Peking University for supporting the computational workthe support of BMS Junior Fellow program。
文摘Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.
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.
基金the Natural Science Foundation of Shandong Province(Nos.ZR2022JQ05 and ZR2024MF010).
文摘With high surface-to-volume ratio,the abundant surface states and high carrier concentration are challenging the nearinfrared photodetection behaviors of narrow band gap semiconductors nanowires.In this study,the narrow band gap semiconductor of Bi_(2)O_(2)Se nanosheets(NSs)is adopted to construct mixed-dimensional heterojunctions with GaSb nanowires(NWs)for demonstrating the impressive self-powered NIR photodetection.Benefiting from the built-in electric field of~140 meV,the as-constructed NW/NS mixeddimensional heterojunction self-powered photodetector shows the low dark current of 0.07 pA,high I_(light)/I_(dark)ratio of 82 and fast response times of<2/2 ms at room temperature.The self-powered photodetector performance can be further enhanced by fabricating the NW array/NS mixed-dimensional heterojunction by using a contact printing technique.The excellent photodetection performance promises the asconstructed NW/NS mixed-dimensional heterojunction self-powered photodetector in imaging and photocommunication.
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.
