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Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus
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作者 Se In Kim Woong-Ju Kim +1 位作者 Jin Gu Kang Dong-Wan Kim 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期618-637,共20页
Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy storage.Herein,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-... Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy storage.Herein,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-SX),are employed as Li-ion battery anodes.Via thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal structure.Further,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-H tetrahedra.The resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)H vacancies.The doping concentrations are varied by controlling the amount of precursors or their mean free paths.Even at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 cycles.These improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state diffusion.The approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage. 展开更多
关键词 Li-ion battery Two-dimensional n-type siloxene Doping mechanism KINETICS
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Hot-Carrier Effects on Total Dose Irradiated 65 nm n-Type Metal-Oxide-Semiconductor Field-Effect Transistors 被引量:1
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作者 郑齐文 崔江维 +3 位作者 周航 余德昭 余学峰 郭旗 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期117-119,共3页
The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors (nMOSFETs) is investigated. Experimental results show that hot-carrier degradati... The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors (nMOSFETs) is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation (STI). The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect. 展开更多
关键词 of NM in Hot-Carrier Effects on Total Dose Irradiated 65 nm n-type Metal-Oxide-semiconductor Field-Effect Transistors STI on IS
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Electromechanical and photoelectric properties of a novel semiconducting Janus InGaSSe monolayer
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作者 Li Zhong Xiaobao Li +1 位作者 Wei Wang Xinle Xiao 《Journal of Semiconductors》 EI CAS CSCD 2023年第1期85-93,共9页
In recent years,Janus two-dimensional(2D)materials have received extensive research interests because of their outstanding electronic,mechanical,electromechanical,and optoelectronic properties.In this work,we explore ... In recent years,Janus two-dimensional(2D)materials have received extensive research interests because of their outstanding electronic,mechanical,electromechanical,and optoelectronic properties.In this work,we explore the structural,electromechanical,and optoelectronic properties of a novel hypothesized Janus InGaSSe monolayer by means of first-principles calculations.It is confirmed that the Janus InGaSSe monolayer indeed show extraordinary charge transport properties with intrinsic electron mobility of 48139 cm^(2)/(V·s)and hole mobility of 16311 cm^(2)/(V·s).Both uniaxial and biaxial strains can effectively tune its electronic property.Moreover,the Janus InGaSSe monolayer possesses excellent piezoelectric property along both inplane and out-of-plane directions.The results of this work imply that the Janus InGaSSe monolayer is in fact an efficient photocatalyst candidate,and may provide useful guidelines for the discovery of other new 2D photocatalytic and piezoelectric materials. 展开更多
关键词 Janus InGaSSe monolayer semiconductING photocatalyst PIEZOELECTRICITY
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Semiconducting single-walled carbon nanotubes synthesized by S-doping 被引量:5
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作者 Z.J.Li L.Wang +2 位作者 Y.J.Su P.Liu Y.F.Zhang 《Nano-Micro Letters》 SCIE EI CAS 2009年第1期9-13,共5页
An approach was presented for synthesis of semiconducting single-walled carbon nanotubes(SWNTs) by sulfur(S) doping with the method of graphite arc discharge. Raman spectroscopy, UV-vis-NIR absorption spectroscopy and... An approach was presented for synthesis of semiconducting single-walled carbon nanotubes(SWNTs) by sulfur(S) doping with the method of graphite arc discharge. Raman spectroscopy, UV-vis-NIR absorption spectroscopy and electronic properties measurements indicated the semconducting properties of the SWNTs samples. Simulant calculation indicated that S doping could induce convertion of metallic SWNTs into semiconducting ones. This strategy may pave a way for the direct synthesis of pure semiconducting SWNTs. 展开更多
关键词 S-doping SINGLE-WALL Carbon nanotubes semiconductING Arc discharge
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SEMICONDUCTING AND METALLIC POLYMERS:THE FOURTH GENERATION OF POLYMERIC MATERIALS 被引量:45
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作者 AlanJ.Heeger 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第6期545-572,共28页
INTRODUCTIONIn 1976, Alan MacDiarmid, Hideki Shirakawa and I, together with a talented group of graduate students andpost-doctoral researchers discovered conducting polymers and the ability to dope these polymers over... INTRODUCTIONIn 1976, Alan MacDiarmid, Hideki Shirakawa and I, together with a talented group of graduate students andpost-doctoral researchers discovered conducting polymers and the ability to dope these polymers over the fullrange from insulator to metal. This was particularly exciting because it created a new field of research on theboundary between chemistry and condensed matter physics, and because it created a number of opportunities: 展开更多
关键词 POLY semiconductING AND METALLIC POLYMERS
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Semiconducting Mineral Photocatalytic Regeneration of Fe^(2+) Promotes Carbon Dioxide Acquisition by Acidithiobacillus ferrooxidans 被引量:2
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作者 LI Yan LU Anhuai +2 位作者 WANG Xin DING Hongrui WANG Changqiu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第3期761-766,共6页
Chemoautotrophic organisms have once been excluded from the development of universally applicable CO2 fixation technology due to its low production yields of biomass. In this study, we used Acidithiobacillusferrooxida... Chemoautotrophic organisms have once been excluded from the development of universally applicable CO2 fixation technology due to its low production yields of biomass. In this study, we used Acidithiobacillusferrooxidans (A.f.) as a model chemoautotrophic microorganism to test the hypothesis that exogenetic photoelectrons from semiconducting mineral photocatalysis can enable the regeneration of Fe^2+ that could be then used by A.f. and support its growth. In a simulated electrochemical system, where exogenetic electrons were provided by an electrochemical approach, an accelerated growth rate of A.f. was observed as compared with that in traditional batch cultivation. In a coupled system, where light-irradiated natural rutile provided the primary electron source to feed A.f., the bacterial growth rate as well as the subsequent CO2 fixation rate was demonstrated to be in a light-dependent manner. The sustaining flow of photogenerated electrons from semiconducting mineral to bacteria provided an inexhaustible electron source for chemoautotrophic bacteria growth and CO2 fixation. This finding might contribute to the development of novel effective CO2 fixation technology. 展开更多
关键词 CO2 fixation PHOTOCATALYSIS chemoautotrophic organisms semiconducting mineral
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Noticeable positive Doppler effect on optical bistability in an N-type active Raman gain atomic system 被引量:2
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作者 常增光 钮月萍 +1 位作者 张敬涛 龚尚庆 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第11期280-284,共5页
We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion... We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type. 展开更多
关键词 positive Doppler effect optical bistability n-type atomic system active Raman gain
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RBC Membrane Camouflaged Semiconducting Polymer Nanoparticles for Near-Infrared Photoacoustic Imaging and Photothermal Therapy 被引量:4
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作者 Dongye Zheng Peiwen Yu +3 位作者 Zuwu Wei Cheng Zhong Ming Wu Xiaolong Liu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第7期218-234,共17页
Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated ... Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation. 展开更多
关键词 semiconducting conjugated polymer nanoparticles Red blood cell membrane camouflage Deep tumor penetration Photoacoustic imaging Photothermal therapy
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Analytical Descriptions of Magnetic Properties and Magnetoresistance in n-Type HgCr_2Se_4 被引量:2
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作者 林朝镜 石友国 李永庆 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期157-160,共4页
We present a detailed investigation of magnetic properties of colossal magnetoresistance material HgCr2Se4. While spontaneous magnetization and zero-field magnetic susceptibility are found to follow asymptotic scaling... We present a detailed investigation of magnetic properties of colossal magnetoresistance material HgCr2Se4. While spontaneous magnetization and zero-field magnetic susceptibility are found to follow asymptotic scaling laws for a narrow range of temperatures near the critical point, two methods with connections to the renormalization group theory provide analytical descriptions of the magnetic properties for much wider temperature ranges. Based on this, an analytical formula is obtained for the temperature dependence of the low field magnetoresistance in the paramagnetic phase. 展开更多
关键词 of on de is ET Analytical Descriptions of Magnetic Properties and Magnetoresistance in n-type HgCr2Se4 in for
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New CMOS compatible super-junction LDMOST with n-type buried layer 被引量:1
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作者 段宝兴 张波 李肇基 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第12期3754-3759,共6页
A new super-junction lateral double diffused MOSFET (LDMOST) structure is designed with n-type charge compensation layer embedded in the p^--substrate near the drain to suppress substrate-assisted depletion effect t... A new super-junction lateral double diffused MOSFET (LDMOST) structure is designed with n-type charge compensation layer embedded in the p^--substrate near the drain to suppress substrate-assisted depletion effect that results from the compensating charges imbalance between the pillars in the n-type buried layer. A high electric field peak is introduced in the surface by the pn junction between the p^--substrate and n-type buried layer, which given rise to a more uniform surface electric field distribution by modulation effect. The effect of reduced bulk field (REBULF) is introduced to improve the vertical breakdown voltage by reducing the high bulk electric field around the drain, The new structure features high breakdown voltage, low on-resistance and charges balance in the drift region due to n-type buried layer. 展开更多
关键词 super-junction LDMOST n-type buried layer REBULF breakdown voltage
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Uniaxial stress influence on lattice,band gap and optical properties of n-type ZnO:first-principles calculations 被引量:1
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作者 杨平 李培 +4 位作者 张立强 王晓亮 王欢 宋喜福 谢方伟 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期399-403,共5页
The lattice, the band gap and the optical properties of n-type ZnO under uniaxial stress are investigated by first- principles calculations. The results show that the lattice constants change linearly with stress. Ban... The lattice, the band gap and the optical properties of n-type ZnO under uniaxial stress are investigated by first- principles calculations. The results show that the lattice constants change linearly with stress. Band gaps are broadened linearly as the uniaxial compressive stress increases. The change of band gap for n-type ZnO comes mainly from the contribution of stress in the c-axis direction, and the reason for band gap of n-type ZnO changing with stress is also explained. The calculated results of optical properties reveal that the imaginary part of the dielectric function decreases with the increase of uniaxial compressive stress at low energy. However, when the energy is higher than 4.0 eV, the imaginary part of the dielectric function increases with the increase of stress and a blueshift appears. There are two peaks in the absorption spectrum in an energy range of 4.0-13.0 eV. The stress coefficient of the band gap of n-type ZnO is larger than that of pure ZnO, which supplies the theoretical reference value for the modulation of the band gap of doped ZnO. 展开更多
关键词 uniaxial stress FIRST-PRINCIPLES optical properties n-type ZnO
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Obtaining the thin Semiconductive Covering Re-Se From Sulphate Electrolyte 被引量:1
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作者 E.A. Salakhova A.M. Aliyev 《Advances in Materials Physics and Chemistry》 2012年第4期253-255,共3页
There have been investigated the kinetics and mechanism of the cathode electrodeposition of thin coverings Re-Se?from the sulphate electrolyte, containing NH4ReO4, SeO2 and H2SO4. On the base of X-ray phase analysis a... There have been investigated the kinetics and mechanism of the cathode electrodeposition of thin coverings Re-Se?from the sulphate electrolyte, containing NH4ReO4, SeO2 and H2SO4. On the base of X-ray phase analysis and by the method of cyclic avometry there have been determined the content of obtained coverings, electrosettled at the various concentrations of components in electrolyte. The co-deposition process was shown to be attended by depolarization, which is due to the energy release upon the formation of the alloy. 展开更多
关键词 ELECTRODEPOSITION Alloys RHENIUM SELEN semiconductive COVER
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Recent development of n-type thermoelectric materials based on conjugated polymers 被引量:1
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作者 Bin Meng Jun Liu Lixiang Wang 《Nano Materials Science》 CAS CSCD 2021年第2期113-123,共11页
Thermoelectric(TE)materials based on conjugated polymers have received much attention due to their great advantages of solution processibility,light weight,flexibility,and low thermal conductivity.These advantages mak... Thermoelectric(TE)materials based on conjugated polymers have received much attention due to their great advantages of solution processibility,light weight,flexibility,and low thermal conductivity.These advantages make them potential candidates for large-area,low-cost and low-power TE applications.Both efficient p-type and n-type conjugated polymers with high and comparable thermoelectric performance are required for practical TE applications.However,due to the inefficient n-doping efficiency and unstable electron transport of most n-type conjugated polymers,the TE performance of n-type polymers is much poorer than that of their p-type counterparts,impeding the development of polymer TE materials.Great efforts have been made to address the low ndoping efficiency and TE performance of n-type polymers,including the chemical modification of traditional ntype polymers,the design of new n-type conjugated polymers,and the development of more efficient n-dopants,as well as doping engineering.Nowadays,the TE performance of n-type polymers has been greatly improved,indicating a bright future for polymer TE materials.In this review,we summarize the recent progress made on ntype polymer TE materials,mainly focusing on the structure-performance relationships based on promising n-type polymers for TE applications.This review aims to provide some guidelines for future material design. 展开更多
关键词 Polymer thermoelectrics n-type polymers N-DOPING CONDUCTIVITY Power facto
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A"donor–acceptor"structured semiconductor polymer for near infrared fluorescence imaging guided photodynamic therapy 被引量:1
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作者 Baoling Li Ting Xu +5 位作者 Xiaosha Wang Shaojing Zhao Benhua Wang Lihui Jiang Xiangzhi Song Minhuan Lan 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2022年第4期75-85,共11页
Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selec... Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selectivity,and minimal invasiveness.For this,photosensitizers with NIR fluorescence emission and high^(1)O_(2)generation quantum yield are highly desirable.Herein,we designed and synthesized a"donor-acceptor"(D-A)structured semiconductor polymer(SP),which was then wrapped with an amphiphilic compound(Pluronic■F127)to prepare water-soluble nanoparticles(F-SP NPs).The obtained F-SP NPs exhibit good water solubility,excellent particle size stability,strong absorbance at deep red region,and strong NIR fluorescent emission characteristics.The maximal mass extinction coe±cient and fluorescence quantum yield of these F-SPs were calculated to be 21.7 L/(g·cm)and 6.5%,respectively.Moreover,the^(1)O_(2)quantum yield of 89%for F-SP NPs has been achieved under 635 nm laser irradiation,which is higher than Methylene Blue,Ce6,and PpIX.The outstanding properties of these F-SP NPs originate from their unique D-A molecular characteristic.This work should help guide the design of novel semiconductor polymer for NIR fluorescent imaging guided PDT applications. 展开更多
关键词 Donor-acceptor structure semiconducting polymer nanoparticles photodynamic therapy near infrared fluorescence imaging
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Majorana fermions induced fast-and slow-light in a hybrid semiconducting nanowire/superconductor device 被引量:1
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作者 陈华俊 朱鹏杰 +1 位作者 陈咏雷 侯宝成 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期598-605,共8页
We investigate theoretically Rabi-like splitting and Fano resonance in absorption spectra of quantum dots(QDs)based on a hybrid QD-semiconducting nanowire/superconductor(SNW/SC)device mediated by Majorana fermions(MFs... We investigate theoretically Rabi-like splitting and Fano resonance in absorption spectra of quantum dots(QDs)based on a hybrid QD-semiconducting nanowire/superconductor(SNW/SC)device mediated by Majorana fermions(MFs).Under the condition of pump on-resonance and off-resonance,the absorption spectrum experiences the conversion from Fano resonance to Rabi-like splitting in different parametric regimes.In addition,the Fano resonances are accompanied by the rapid normal phase dispersion,which will indicate the coherent optical propagation.The results indicate that the group velocity index is tunable with controlling the interaction between the QD and MFs,which can reach the conversion between the fast-and slow-light.Fano resonance will be another method to detect MFs and our research may indicate prospective applications in quantum information processing based on the hybrid QD-SNW/SC devices. 展开更多
关键词 majorana fermions Fano resonance slow and fast light hybrid semiconducting/superconductor device
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Modeling of a triple reduced surface field silicon-on-insulator lateral double-diffused metal–oxide–semiconductor field-effect transistor with low on-state resistance 被引量:1
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作者 王裕如 刘祎鹤 +4 位作者 林兆江 方冬 李成州 乔明 张波 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期430-435,共6页
An analytical model for a novel triple reduced surface field(RESURF) silicon-on-insulator(SOI) lateral doublediffused metal–oxide–semiconductor(LDMOS) field effect transistor with n-type top(N-top) layer, wh... An analytical model for a novel triple reduced surface field(RESURF) silicon-on-insulator(SOI) lateral doublediffused metal–oxide–semiconductor(LDMOS) field effect transistor with n-type top(N-top) layer, which can obtain a low on-state resistance, is proposed in this paper. The analytical model for surface potential and electric field distributions of the novel triple RESURF SOI LDMOS is presented by solving the two-dimensional(2D) Poisson's equation, which can also be applied to single, double and conventional triple RESURF SOI structures. The breakdown voltage(BV) is formulized to quantify the breakdown characteristic. Besides, the optimal integrated charge of N-top layer(Q_(ntop)) is derived, which can give guidance for doping the N-top layer. All the analytical results are well verified by numerical simulation results,showing the validity of the presented model. Hence, the proposed model can be a good tool for the device designers to provide accurate first-order design schemes and physical insights into the high voltage triple RESURF SOI device with N-top layer. 展开更多
关键词 analytical model triple reduced surface field (RESURF) silicon-on-insulator (SOI) n-type top (N-top) layer
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Structure and Semiconducting Character of a Polymeric Iodoplumbate Coordination Complex
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作者 宋德生 刘长春 +2 位作者 陈恒隽 苏东坡 傅志勇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第8期1142-1146,共5页
A new polymeric iodoplumbate complex [Zn(DMF)6][Pb2I6] 1 has been prepared and characterized by elemental analysis and single-crystal X-ray analysis. Its structure contains infinite iodoplumbate chains constructed b... A new polymeric iodoplumbate complex [Zn(DMF)6][Pb2I6] 1 has been prepared and characterized by elemental analysis and single-crystal X-ray analysis. Its structure contains infinite iodoplumbate chains constructed by the [PbI5] subunit. EHT crystal orbital calculation and the experimental results show that this material is an unconventional semiconductor and the electrical character is associated with its structural feature. 展开更多
关键词 iodoplumbate coordination polymer structure and characterization semiconducting property
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Photoactive materials based on semiconducting nanocarbons——A challenge opening new possibilities for photocatalysis
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作者 Siglinda Perathoner Claudio Ampelli +3 位作者 Shiming Chen Rosalba Passalacqua Dangsheng Su Gabriele Centi 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第2期207-218,共12页
This perspective paper introduces the concept that nanocarbons and related materials such as carbon dots are an interesting intrinsic photocatalytic semiconducting material, and not only a modifier of the existing (se... This perspective paper introduces the concept that nanocarbons and related materials such as carbon dots are an interesting intrinsic photocatalytic semiconducting material, and not only a modifier of the existing (semiconducting) materials to prepare hybrid materials. The semiconducting properties of the nanocarbons, and the possibility to have the band gap within the visible-light region through defect band engineering, introduction of light heteroatoms and control/manipulation of the curvature or surface functionalization are discussed. These materials are conceptually different from the 'classical' semiconducting photocatalysts, because semiconductor domains with tuneable characteristics are embedded in a conductive carbon matrix, with the presence of various functional groups (as C=0 groups) enhancing charge separation by trapping electrons. These nanocarbons open a range of new possibilities for photocatalysis both for energetic and environmental applications. The use of nanocarbons as quantum dots and photo luminescent materials was also analysed. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved. 展开更多
关键词 NANOCARBON Carbon-type photocatalysts semiconducting nanocarbons Carbon nano-dots Water splitting CO2 photoreduction
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Modulating Bandgap and HOCO/LUCO Energy of Semiconducting Polymer by Copolymerization or Incorporation of Electron Withdrawing/Releasing Groups
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作者 YAN Liu-ming LU Wen-cong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第5期598-601,共4页
The modulation of bandgap and HOCO/LUCO energies of conjugated polymers by copolymerization or by incorporation of electron withdrawing/releasing groups is studied.The study was conducted by band structure calculation... The modulation of bandgap and HOCO/LUCO energies of conjugated polymers by copolymerization or by incorporation of electron withdrawing/releasing groups is studied.The study was conducted by band structure calculation applying density functional theory with generalized gradient approximation.The polymers and copolymers were modeled as 1D infinite system with periodical boundary condition along the molecular direction.It is concluded that the bandgap and HOCO/LUCO energies of conjugated polymers depend on both electron withdrawing/releasing effects and non-bonding interaction between a side group and the conjugated systems. 展开更多
关键词 Ab initio calculation Density functional theory Band structure semiconducting polymer Low bandgap
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Applications of Secondary Electron Composition Contrast Imaging Method in Microstructure Studies on Heterojunction Semiconductor Devices and Multilayer Materials
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作者 刘安生 邵贝羚 +2 位作者 安生 王敬 刘铮 《Rare Metals》 SCIE EI CAS CSCD 1999年第2期2-8,共7页
The principle, imaging condition and experimental method for obtaining high resolution composition contrast in secondary electron image were described. A new technique of specimen preparation for secondary electron co... The principle, imaging condition and experimental method for obtaining high resolution composition contrast in secondary electron image were described. A new technique of specimen preparation for secondary electron composition contrast observation was introduced and discussed. By using multilayer P+Si1-xGex/pSi heterojunction internal photoemission infrared detector as an example, the applications of secondary electron composition contrast imaging in microstructure studies on heterojunction semiconducting materials and devices were stated. The characteristics of the image were compared with the ordinary transmission electron diffraction contrast image. The prospects of applications of the imaging method in heterojunction semiconductor devices and multilayer materials are also discussed. 展开更多
关键词 Secondary electron composition contrast image Heterojunction semiconducting devices Multilayer materials Electron microscopy MICROSTRUCTURE
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