半导体所最新SCI论文（2019-8-15） [2019-08-16] |
| Record 1 of 13 Individual Identification Based on Code-ModulatedVisual-Evoked Potentials
Authors: Zhao, HZ; Wang, YJ; Liu, ZD; Pei, WH;Chen, HD IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY Volume: 14 Issue: 12 Pages: 3206-3216 Published: DEC2019 Language: English Documenttype: Article DOI: 10.1109/TIFS.2019.2912272 Abstract: The electroencephalography (EEG) method has recentlyattracted increasing attention in the study of brain activity-based biometricsystems because of its simplicity, portability, noninvasiveness, and relativelylow cost. However, due to the low signal-to-noise ratio of EEG, most of theexisting EEG-based biometric systems require a long duration of signals toachieve high accuracy in individual identification. Besides, the feasibilityand stability of these systems have not yet been conclusively reported, sincemost studies did not perform longitudinal evaluation. In this paper, weproposed a novel EEG-based individual identification method usingcode-modulated visual-evoked potentials (c-VEPs). Specifically, this paperquantitatively compared eight code-modulated stimulation patterns, includingsix 63-bit (1.05 s at 60-Hz refresh rate) m-sequences (M1-M6) and two spatiallycombined sequence groups (M x 4: M1-M4 and M x 6: M1-M6) in recording thec-VEPs from a group of 25 subjects for individual identification. To furtherevaluate the influence of inter-session variability, we recorded two datasessions for each individual on different days to measure intra-session andcross-session identification performance. State-of-the-art VEP detectionalgorithms in brain-computer interfaces (BCIs) were employed to construct atemplate-matching-based identification framework. For intra-sessionidentification, we achieved a 100% correct recognition rate (CRR) using 5.25-sEEG data (average of five trials for M5). For cross-session identification,99.43% CRR was attained using 10.5-s EEG signals (average of ten trials forM5). These results suggest that the proposed c-VEPbased individualidentification method is promising for real-world applications.
Record 2 of 13 Selective Oxygen Sensor Prepared Using Ni-doped ZincFerrite Nanoparticles
Authors: Fareed, S; Jamil, A; Afsar, F; Sher, F;Li, CB; Xu, XL; Rafiq, MA JOURNAL OF ELECTRONIC MATERIALS Volume: 48 Issue: 9 Pages: 5677-5685 Published: SEP2019 Language: English Documenttype: Article DOI: 10.1007/s11664-019-07389-y Abstract: In this work, pure and Ni-doped zinc ferritenanoparticles, Zn(1-x)NixFe2O4 (x=0.02, 0.04 and 0.06), were prepared bycoprecipitation followed by calcination. X-ray diffraction (XRD) analysisrevealed the shrinkage in the lattice by incorporation of Ni in zinc ferritenanoparticles. The prepared nanoparticles were 25-100nm in size as revealed byscanning electron microscopy. Oxygen sensing characteristics were evaluated forall the prepared compositions. The results showed an increase in the responseof the sensors towards oxygen by Ni doping. The increase in response may beattributed to the increase in oxygen adsorption on the particles surface by Nidoping. The response time of Zn0.96Ni0.04Fe2O4 was lowest and was 10s for400ppm oxygen concentration at 180 degrees C. Recovery time of Ni-dopedconcentrations was lower than the pure zinc ferrite nanoparticles sensor. Theresponse of Ni-doped zinc ferrite nanoparticles sensors was stable than that ofthe pure zinc ferrite.
Record 3 of 13 A Dual-Slot Electro-Optic Modulator Based on anEpsilon-Near-Zero Oxide
Authors: Kuang, YX; Liu, Y; Tian, LF; Han, WH;Li, ZY IEEE PHOTONICS JOURNAL Volume: 11 Issue: 4 Published: AUG2019 Language: English Documenttype: Article DOI: 10.1109/JPHOT.2019.2927756 Abstract: A dual-slot silicon electro-optic modulator based onindium tin oxide is proposed with high modulation efficiency, low loss, andbroadband operation leveraging the epsilon-near-zero (ENZ) effect. The designis verified by numerical simulation with Lumerical Solutions. The activemodulation region consists of two slots for enhancing the overlap between theoptical mode and the ENZ region to improve the performance of theelectro-absorption modulator. By combining the confinement of the dual-slotwaveguide and the ENZ effect, we can obtain a high modulation efficiency of1.44 dB/mu m at the wavelength of 1.55 mu m. The modulator with a modulationregion length of only 10 mu m demonstrates a low insertion loss and a highextinction ratio, with the corresponding values of 0.37 and 14.4 dB,respectively. Through the optimized design, the efficient coupling can beachieved between the silicon waveguide and the dual-slot waveguide with thecoupling loss of only 0.12 dB. Moreover, the modulator can operate in a wide spectrum,covering the S-, C-, and L-band. The dual-slot electro-optic modulator thusprovides various merits including high modulation efficiency, ultracompactfootprint, broad optical bandwidth, and complementary metal-oxide-semiconductorcompatibility.
Record 4 of 13 A Novel Multiple-Frequency RF-MEMS Resonator Based on theWhispering Gallery Modes
Authors: Kan, X; Chen, ZJ; Yuan, Q; Wang, FX;Yang, JL; Yang, FH IEEE TRANSACTIONS ON ELECTRON DEVICES Volume: 66 Issue: 8 Pages: 3683-3685 Published: AUG2019 Language: English Documenttype: Article Abstract: A novel microelectromechanical system (MEMS) diskresonator based on the whispering gallery modes (WGMs) has been demonstrated.With the optimized structure of the multi-electrodes, multiple WGMs can beeasily excited by a pair of electrodes. For a disk resonator of 37 mu m inradius, resonance frequencies of 56-170 MHz and high-quality factor (Q) around10 000 in the atmosphere are obtained. In themeantime, a singleWGMcan berealized under a specific electrodes connection. Multiple-frequency outputsfrom the single resonator could dramatically simplify the communication systemand reduce the power consumption of a digital system.
Record 5 of 13
Authors: Meng, L; Yang, XG; Chai, HY; Lv, ZR;Yang, T ACS APPLIED MATERIALS & INTERFACES Volume: 11 Issue: 29 Pages: 26491-26499 Published: JUL24 2019 Language: English Documenttype: Article Abstract: High-work function (WE) transparent conductive thin filmsimprove the performance of solar cells and organic light-emitting diodes byfacilitating interfacial charge carrier transport. Al-doped ZnO (AZO) becomes avery promising transparent conductive material because of nontoxicity, abundantmaterial resources, and low cost. To increase the WF of AZO without enhancingthe series resistance of the device, a high-WF and low-resistance surfacemodifier of polycrystalline zinc molybdenum oxide (ZMO) was developed byutilizing thermal evaporation of MoO3 on the surface of AZO and a subsequenttwo-step annealing treatment. The first step of air annealing causes theformation of monoclinic ZnMoO4 nanocrystals in the ZMO modifier. This improvesthe WF of AZO from 3.83 to 4.86 eV by increasing the group electronegativityand cation oxidation state. Furthermore, the second step of N-2 annealingdecreases the resistivity of the polycrystalline ZMO by increasing the donorstates of oxygen vacancies. The surface modification effect is verified byapplying the ZMO-modified AZO to the front electrode of hydrogenated amorphoussilicon thinfilm solar cells. The low-resistance polycrystalline ZMO modifiernot only increases light harvesting in the solar cells by improving interfacialrefractive index matching but also improves the open-circuit voltage bymodifying the interfacial band alignment. In particular, the modifier increasesthe fill factor by ca. 13% by reducing the series resistance of the device.These enable a gain of ca. 23% in photoelectric conversion efficiency comparedto the unmodified AZO. The results suggest the feasibility to tune the WF andconductivity of a material independently.
Record 6 of 13
Authors: Xue, XD; Zhu, LP; Huang, W; Marie, X;Renucci, P; Liu, Y; Zhang, Y; Zeng, XL; Wu, J; Xu, B; Wang, ZG; Chen, YH;Zhang, WF; Lu, Y PHYSICAL REVIEW B Volume: 100 Issue: 4 Published: JUL23 2019 Language: English Documenttype: Article DOI: 10.1103/PhysRevB.100.045417 Abstract: We have measured a helicity-dependent photocurrent atzero external magnetic field in a device based on a semiconductor quantum wellembedded in a p-i-n junction. The device is excited under vertical incidencewith circularly polarized light. The spin filtering effect is evidenced in thetemperature range 77-300 K owing to a CoFeB/MgO spin filter with out-of-planemagnetization in remanence. The helicity-dependent photocurrent is explored asa function of the temperature and bias. These characteristics are compared withthose of a spin photocurrent device with in-plane magnetized CoFeB/MgO spinfilter, excited under oblique incidence with circularly polarized light. Incontrast to the in-plane spin filter device, the circularly polarized lightasymmetry of the photocurrent in the out-of-plane device depends weakly on theexternal bias. The two devices are sensitive to the spin filtering of eitherthe in-plane (S-x) or out-of-plane (S-z) photogenerated electron spin in thesemiconductor quantum well. The helicity-dependent photocurrent results can beexplained by the Dyakonov-Perel electron spin-relaxation mechanism. Our studyreveals the giant spin relaxation anisotropy in III-V zinc-blende quantum wellsin the presence of a vertical electric field.
Record 7 of 13 Strain compensated robust semiconductor saturableabsorber mirror for fiber lasers
Authors: Wang, Y; Lin, N; Gao, WL; Song, HY; Hu,ML; Li, HM; Bao, WX; Ma, XY; Zhang, ZG CHINESE OPTICS LETTERS Volume: 17 Issue: 7 Published: JUL10 2019 Language: English Documenttype: Article Abstract: We demonstrate a strain compensated long lifetimesemiconductor saturable absorber mirror ( SESAM) with a high modulation depthfor fiber lasers. The SESAM was measured to have a damage threshold of 9.5mJ/cm(2), a modulation depth of 11.5%, a saturation fluence of 39.3 mu J/cm(2),and an inversed saturable absorption coefficient of 630 mJ/cm(2). The SESAM hasbeen applied to a linear cavity mode-locked Yb-doped fiber laser, which hasbeen working for more than a year without damage of the SESAM.
Record 8 of 13 Highly Polarized Photoelectrical Response in vdW ZrS3Nanoribbons
Authors: Wang, XT; Wu, KD; Blei, M; Wang, Y; Pan,LF; Zhao, K; Shan, CX; Lei, M; Cui, Y; Chen, B; Wright, D; Hu, WD; Tongay, S;Wei, ZM ADVANCED ELECTRONIC MATERIALS Volume: 5 Issue: 7 Published: JUL2019 Language: English Documenttype: Article Abstract: 2D anisotropic materials, such as black phosphorus, ReS2,and GaTe, have been shown to exhibit exciting direction- andpolarization-sensitive material properties. Highly crystallinechemical-vapor-transport-grown ZrS3 crystals exhibit large optical-absorption-coefficientanisotropy, which doubles under resonance conditions. The observed opticalanisotropy manifests itself in angle-resolved photocurrent density polar plotswith dichroic ratio (I-pb/I-pa) of 1.73 excited by a laser source of lambda =450 nm and 1.14 by lambda = 532 nm. The optical absorption and electronicdichroic response are fully explained through detailed band structure andpolarization-sensitive optical-absorption-spectrum calculations. Not only isthe family of 2D anisotropic semiconductors expanded into Zr-basedtrichalcogenides but fundamental insights on how crystalline anisotropy,optical absorption dichroism, and generated photocurrents are interrelated invan der Waals Zr-based trichalcogenides materials are also provided.
Record 9 of 13
Authors: Cai, CY; Zhao, YH; Xie, SW; Zhao, XB;Zhang, Y; Xu, YQ; Liang, CY; Niu, ZC; Shi, Y; Li, YS; Che, RC SMALL Volume: 15 Issue: 27 Published: JUL2019 Language: English Documenttype: Article Abstract: Interfaces in semiconductor heterostructures is ofcontinuously greater significance in the trend of scaling materials down to theatomic limit. Since atoms tend to behave more irregularly around interfacesthan in internal materials, accurate energy band alignment becomes a majorchallenge, which determines the ultimate performance of devices. Therefore, acomprehensive understanding of the interplay between heterointerface, energyband, and macro-performance is desiderated. Here, such interplay is explored byinvestigating asymmetric heterointerfaces with identical fabrication parametersin multiple-quantum-well lasers. The unexpected asymmetry derives from theatomic discrepancy around heterointerfaces, which ultimately improves theoptical property through altered valence band offsets. Strain and chargedistribution around heterointerfaces are characterized via geometric phaseanalysis and in situ bias electron holography, respectively. Combiningexperiments with theories, arsenic-enrichment at one of the interfaces isconsidered the origin of asymmetry. To reveal actual band alignment, valenceband model is modified focusing on the transition around heterojunctions. Theenhanced photoluminescence intensity reflects the alleviation of holeconfinement insufficiency and the enlargement of valence band offset. Theresults help to advance the understanding of the general problem of interfacein nanostructures and provide guidance applicable to various scenarios formicro-macro correlation.
Record 10 of 13
Authors: Ci, HN; Chang, HL; Wang, RY; Wei, TB;Wang, YY; Chen, ZL; Sun, YW; Dou, ZP; Liu, ZQ; Li, JM; Gao, P; Liu, ZF ADVANCED MATERIALS Volume: 31 Issue: 29 Published: JUL2019 Language: English Documenttype: Article Abstract: For III-nitride-based devices, such as high-brightnesslight-emitting diodes (LEDs), the poor heat dissipation of the sapphiresubstrate is deleterious to the energy efficiency and restricts many of theirapplications. Herein, the role of vertically oriented graphene (VG) nanowallsas a buffer layer for improving the heat dissipation in AlN films on sapphiresubstrates is studied. It is found that VG nanowalls can effectively enhancethe heat dissipation between an AlN film and a sapphire substrate in the longitudinaldirection because of their unique vertical structure and good thermalconductivity. Thus, an LED fabricated on a VG-sapphire substrate shows a 37%improved light output power under a high injection current (350 mA) with aneffective 3.8% temperature reduction. Moreover, the introduction of VGnanowalls does not degrade the quality of the AlN film, but instead promotesAlN nucleation and significantly reduces the epilayer strain that is generatedduring the cooling process. These findings suggest that the VG nanowalls can bea good buffer layer candidate in III-nitride semiconductor devices, especiallyfor improving the heat dissipation in high-brightness LEDs.
Record 11 of 13 Performance Improvement of GaN Based Laser Diode UsingPd/Ni/Au Metallization Ohmic Contact
Authors: Wang, WJ; Xie, WZ; Deng, ZJ; Yang, HJ;Liao, ML; Li, JZ; Luo, XJ; Sun, S; Zhao, DG COATINGS Volume: 9 Issue: 5 Published: MAY2019 Language: English Documenttype: Article Abstract: We report an investigation of the effects of differentmetal systems and surface treatment on the contact performance of GaN lasers.We found that multi-element metal alloy and surface chemical treatment are thekeys to achieve good ohmic behavior contacts on GaN laser diodes. Pd/Ni/Aucontact demonstrates excellent thermal stability and lowest specific contactresistivity in these metal systems. Properly adjusting the thickness of the Pdand Ni layer and pretreating with the KOH solution can further improve theohmic contact performance. The improved ohmic behavior of the KOH solutionpretreated Pd/Ni/Au contact is attributed to removing surface oxides and thereduction of the schottky barrier heights due to the metal Pd has a high workfunction and the interfacial reactions occurring between the Pd, Ni, Au, andGaN extends into the GaN film. As a result, a low contact resistivity of 1.66 x10(-5) Omega cm(2) can be achieved from Pd(10 nm)/Ni(10 nm)/Au(30 nm) contactswith KOH solution pretreated on top of the laser diode structure. The power ofthe GaN based laser diode with the Pd/Ni/Au metallization ohmic contact can beenhanced by 1.95 times and the threshold current decreased by 37% compared tothat of the conventional ohmic contact Ni/Au.
Record 12 of 13 Self-Powered Flexible Blood Oxygen Monitoring SystemBased on a Triboelectric Nanogenerator
Authors: Chen, HM; Xu, Y; Zhang, JS; Wu, WT;Song, GF NANOMATERIALS Volume: 9 Issue: 5 Published: MAY2019 Language: English Documenttype: Article DOI: 10.3390/nano9050778 Abstract: Flexible optoelectronics based on inorganic functionalcomponents have attracted worldwide attention due to their inherent advantages.However, the power supply problem presents a significant obstacle to thecommercialization of wearable optoelectronics. Triboelectric nanogenerator(TENG) technology has the potential to realize self-powered applicationscompared to the conventional charging technologies. Herein, a flexibleself-powered blood oxygen monitoring system based on TENG was firstdemonstrated. The flexibility of the TENG is mainly due to the inherentproperties of polydimethylsiloxane (PDMS) and the continuously undulatingsurface of crumpled gold (Au) and the rough surface on the electrode and PDMSeffectively increased the output performance. The output voltage, outputcurrent density, and power density were 75.3 V, 7.4 mu A, and 0.2 mW/cm(2),respectively. By etching the sacrificial layer, we then derived a flexibleblood oxygen and pulse detector without any obvious performance degradation. Poweredby the TENG, the detector is mounted onto the thumbnail, from where it detectsa stable photoplethysmography (PPG) signal which can be used to calculate theoxyhemoglobin saturation and pulse rate. This self-powered system provides anew way to sustainably monitor physiological parameters, which paves the wayfor development of wearable electronics and battery-free systems.
Record 13 of 13 A Fast and Universal RFID Tag Anti-Collision Algorithmfor the Internet of Things
Authors: Zhang, GF; Tao, S; Xia, WA; Cai, Q; Gao,WL; Jia, JD; Wen, J IEEE ACCESS Volume: 7 Pages: 92365-92377 Published: 2019 Language: English Documenttype: Article DOI: 10.1109/ACCESS.2019.2927620 Abstract: To address the problems of high computational complexity,inflexible frame length adjustment, and sub-optimal system efficiency of theRFID tag anti-collision algorithms in the Internet-of-Things systems, alow-complexity, and universal fast RFID tag anti-collision algorithm isproposed in this paper. A faster and less-complex tag number estimation methoddepends less on computing and storage resources, making it easier to integrateinto the Internet of Things. Using the concepts of sub-frame and system efficiencypriority, after each sub-frame is identified, the number of tags is estimatedquickly and the frame length is adjusted dynamically to ensure the algorithm'sefficiency. Moreover, the proposed algorithm is fully compatible with the EPCClass-1 Generation-2 standard, which ensures its universality and compatibilitywith the existing systems. The simulation results show that the proposedalgorithm can achieve a system efficiency of 0.3554, a time efficiency of0.7851, and an identification speed of 433 n/s. Compared with the standard Qalgorithm, the performance is improved by 9.691%, 5.002%, and 8.250%,respectively. It is, hence, demonstrated that the proposed algorithm meets therequirements for the rapid identification of the RFID tags in the Internet-of-Thingsapplications.
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