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Liu MY, Hang CZ, Wu XY, Zhu LY, Wen XH, Wang Y, Zhao XF, Lu HL. Investigation of stretchable strain sensor based on CNT/AgNW applied in smart wearable devices. NANOTECHNOLOGY 2022; 33:255501. [PMID: 35299168 DOI: 10.1088/1361-6528/ac5ee6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 03/17/2022] [Indexed: 05/23/2023]
Abstract
Stretchable strain sensor, an important paradigm of wearable sensor which can be attached onto clothing or even human skin, is widely used in healthcare, human motion monitoring and human-machine interaction. Pattern-available and facile manufacturing process for strain sensor is pursued all the time. A carbon nanotube (CNT)/silver nanowire (AgNW)-based stretchable strain sensor fabricated by a facile process is reported here. The strain sensor exhibits a considerable Gauge factor of 6.7, long-term durability (>1000 stretching cycles), fast response and recovery (420 ms and 600 ms, respectively), hence the sensor can fulfill the measurement of finger movement. Accordingly, a smart glove comprising a sensor array and a flexible printed circuit board is assembled to detect the bending movement of five fingers simultaneously. Moreover, the glove is wireless and basically fully flexible, it can detect the finger bending of wearer and display the responses distinctly on an APP of a smart phone or a host computer. Our strain senor and smart glove will broaden the materials and applications of wearable sensors.
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Lu HL, Kang CQ, Meng QY, Hu JR, Melvin SD. Functional and hepatic metabolite changes in aquatic turtle hatchlings exposed to the anti-androgenic fungicide vinclozolin. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 231:113220. [PMID: 35066435 DOI: 10.1016/j.ecoenv.2022.113220] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/12/2022] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Many man-made chemicals that are released into water bodies in agricultural landscapes have been identified as endocrine disruptors and can cause serious impacts on the growth and survival of aquatic species living in these environments. However, very little attention has been paid to their toxicological effects in cultured non-fish species, such as aquatic turtles. We exposed hatchlings of the Chinese soft-shelled turtle (Pelodiscus sinensis) to different concentrations of vinclozolin (0, 5, 50 and 500 μg/L) for 60 days to assess physiological and metabolic impacts of this fungicide. Despite no death occurrence, hatchling turtles exposed to the highest concentration of vinclozolin consumed less food, grew more slowly (resulting in smaller body size after exposure) and performed more poorly in behavioral swimming tests than controls and turtles exposed to lower concentrations. Hepatic metabolite profiles acquired via liquid chromatography-mass spectrometry (LC-MS) revealed multiple metabolic perturbations related to amino acid, lipid, and fatty acid metabolism in animals exposed to environmentally relevant concentrations. Specifically, many critical metabolites involved in energy-related metabolic pathways (such as some intermediates in the tricarboxylic acid cycle, lactate, and some amino acids) were present in livers of hatchling turtles exposed vinclozolin, though at lower concentrations, reflecting energy metabolism dysregulation induced by exposure to this fungicide. Overall, our results suggest that the changes in growth and behavioral performances caused by chronic vinclozolin exposure may be associated with internal physiological and metabolic disorders mediated at the biochemical level.
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Chen D, Wang Z, Hu FC, Shen C, Chi N, Liu W, Zhang DW, Lu HL. Improved electro-optical and photoelectric performance of GaN-based micro-LEDs with an atomic layer deposited AlN passivation layer. OPTICS EXPRESS 2021; 29:36559-36566. [PMID: 34809064 DOI: 10.1364/oe.439596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The quantum efficiency of GaN-based micro-light-emitting diodes (micro-LEDs) is of great significance for their luminescence and detection applications. Optimized passivation process can alleviate the trapping of carriers by sidewall defects, such as dangling bonds, and is regarded as an effective way to improve the quantum efficiency of micro-LEDs. In this work, an AlN passivation layer was prepared by atomic layer deposition to improve the electro-optical and photoelectric conversion efficiency in GaN-based micro-LEDs. Compared to conventional Al2O3 passivation, the AlN passivation process has a stronger ability to eliminate the sidewall defects of micro-LEDs due to the homogeneous passivation interface. Our experiments show that the AlN-passivated device exhibits two orders of magnitude lower forward leakage and a smaller ideality factor, which leads to significantly enhanced external quantum efficiency (EQE). For 25*25 μm2 micro-LEDs, the EQE of the AlN-passivated device was 18.3% and 57.7% higher than that of the Al2O3-passivated device in luminescence application and detection application, respectively.
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Zhao XF, Wen XH, Zhong SL, Liu MY, Liu YH, Yu XB, Ma RG, Zhang DW, Wang JC, Lu HL. Hollow MXene Sphere-Based Flexible E-Skin for Multiplex Tactile Detection. ACS APPLIED MATERIALS & INTERFACES 2021; 13:45924-45934. [PMID: 34520164 DOI: 10.1021/acsami.1c06993] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Skin-like electronics that can provide comprehensively tactile sensing is required for applications such as soft robotics, health monitoring, medical treatment, and human-machine interfaces. In particular, the capacity to monitor the contact parameters such as the magnitude, direction, and contact location of external forces is crucial for skin-like tactile sensing devices. Herein, a flexible electronic skin which can measure and discriminate the contact parameters in real time is designed. It is fabricated by integrating the three-dimensional (3D) hollow MXene spheres/Ag NW hybrid nanocomposite-based embedded stretchable electrodes and T-ZnOw/PDMS film-based capacitive pressure sensors. To the best of our knowledge, it is the first stretchable electrode to utilize the 3D hollow MXene spheres with the essential characteristic, which can effectively avoid the drawbacks of stress concentration and shedding of the conductive layer. The strain-resistance module and the pressure-capacitance module show the excellent sensing performance in stability and response time, respectively. Moreover, a 6 × 6 sensor array is used as a demonstration to prove that it can realize the multiplex detection of random external force stimuli without mutual interference, illustrating its potential applications in biomimetic soft wearable devices, object recognition, and robotic manipulation.
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Kang CQ, Meng QY, Dang W, Lu HL. Divergent incubation temperature effects on thermal sensitivity of hatchling performance in two different latitudinal populations of an invasive turtle. J Therm Biol 2021; 100:103079. [PMID: 34503815 DOI: 10.1016/j.jtherbio.2021.103079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/05/2021] [Accepted: 08/12/2021] [Indexed: 11/19/2022]
Abstract
The incubation temperature for embryonic development affects several aspects of hatchling performance, but its impact on the thermal sensitivity of performance attributes remains poorly investigated. In the present study, Trachemys scripta elegans hatchlings from two different latitudinal populations were collected to assess the effects of different incubation temperatures on the locomotor (swimming speed) and physiological (heart rate) performances, and the thermal sensitivity of these two attributes. The incubation temperature significantly affected the examined physiological traits. Hatchling turtles produced at low incubation temperature exhibited relatively higher cold tolerance (lower body temperatures at which the animals lose the ability to escape from the lethal conditions), and reduced heart rate and swimming speed. Furthermore, the effect of incubation temperature on the thermal sensitivity of swimming speed differed between the low- and high-latitude populations. At relatively high incubation temperatures, the high-latitude hatchling turtles exhibited reduced thermal sensitivities of swimming speed than those of the low-latitude ones. Reduced thermal sensitivity of locomotor performance together with high cold tolerance, exhibited by the high-latitude hatchling turtles potentially reflected local adaptation to relatively colder and more thermally-variable environments.
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Li YC, Li XX, Zeng G, Chen YC, Chen DB, Peng BF, Zhu LY, Zhang DW, Lu HL. High optoelectronic performance of a local-back-gate ReS 2/ReSe 2 heterojunction phototransistor with hafnium oxide dielectric. NANOSCALE 2021; 13:14435-14441. [PMID: 34473171 DOI: 10.1039/d1nr02728j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A high optoelectronic performance ReS2/ReSe2 van der Waals (vdW) heterojunction phototransistor utilizing thin hafnium oxide (HfO2) as a local-back-gate dielectric layer was prepared and studied. The heterojunction-based phototransistor exhibits a superior electrical performance with a large rectification ratio of ∼103. Furthermore, unlike diode-like heterojunction devices, the innovative introduction of a local-back-gate in this phototransistor provides an outstanding gate-tunable capability with an ultra-low off-state current of 433 fA and a high on/off current ratio of over 106. And under optical excitation of a wide spectrum from 400 to 633 nm, an excellent photodetection responsivity at the 104 A W-1 level and the maximum normalized detectivity of 1.8 × 1015 Jones @ 633 nm have been demonstrated. Such high performances are attributed to the band alignment of the type-II heterojunction and the suppression of dark current by the local-back-gate. This work provides a promising reference for two-dimensional (2D) Re-based heterojunction optoelectronic devices.
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Cui LB, Zhang YJ, Lu HL, Liu L, Zhang HJ, Fu YF, Wu XS, Xu YQ, Li XS, Qiao YT, Qin W, Yin H, Cao F. Thalamus Radiomics-Based Disease Identification and Prediction of Early Treatment Response for Schizophrenia. Front Neurosci 2021; 15:682777. [PMID: 34290581 PMCID: PMC8289251 DOI: 10.3389/fnins.2021.682777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/31/2021] [Indexed: 12/15/2022] Open
Abstract
Background Emerging evidence suggests structural and functional disruptions of the thalamus in schizophrenia, but whether thalamus abnormalities are able to be used for disease identification and prediction of early treatment response in schizophrenia remains to be determined. This study aims at developing and validating a method of disease identification and prediction of treatment response by multi-dimensional thalamic features derived from magnetic resonance imaging in schizophrenia patients using radiomics approaches. Methods A total of 390 subjects, including patients with schizophrenia and healthy controls, participated in this study, among which 109 out of 191 patients had clinical characteristics of early outcome (61 responders and 48 non-responders). Thalamus-based radiomics features were extracted and selected. The diagnostic and predictive capacity of multi-dimensional thalamic features was evaluated using radiomics approach. Results Using radiomics features, the classifier accurately discriminated patients from healthy controls, with an accuracy of 68%. The features were further confirmed in prediction and random forest of treatment response, with an accuracy of 75%. Conclusion Our study demonstrates a radiomics approach by multiple thalamic features to identify schizophrenia and predict early treatment response. Thalamus-based classification could be promising to apply in schizophrenia definition and treatment selection.
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Zhang Y, Tao JJ, Chen HY, Lu HL. Preparation of single crystalline AlN thin films on ZnO nanostructures by atomic layer deposition at low temperature. NANOTECHNOLOGY 2021; 32:275704. [PMID: 33740776 DOI: 10.1088/1361-6528/abf074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
The growth of hetero-epitaxial ZnO-AlN core-shell nanowires (NWs) and single crystalline AlN films on non-polar ZnO substrate at temperature of 380 °C by atomic layer deposition (ALD) was investigated. Structural characterization shows that the AlN shells have excellent single-crystal properties. The epitaxial relationship of [0002]ZnO//[0002]AlN, and [10-10]ZnO//[10-10]AlNbetween ZnO core and AlN shell has been obtained. The ZnO NW templates were subsequently removed by annealing treatment in forming gas, resulting in ordered arrays of AlN single-crystal nanotubes. The impact factors on the epitaxial growth of AlN films are thoroughly investigated. It turned out that the growth parameters including lattice mismatch between substrate and AlN, growth temperature, and the polarity of ZnO substrate play important roles on the growth of single-crystal AlN films by ALD. Finally, non-polar AlN films with single-crystalline structure have been successfully grown onm-plane ZnO (10-10) single-crystal substrates. The as-grown hollow AlN nanotubes arrays and non-polar AlN films with single-crystalline structures are suggested to be highly promising for applications in nanoscale devices. Our research has developed a potential method to obtain other inorganic nanostructures and films with single-crystalline structure at fairly low temperature.
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Li XX, Chen XY, Chen JX, Zeng G, Li YC, Huang W, Ji ZG, Zhang DW, Lu HL. Dual-gate MoS 2phototransistor with atomic-layer-deposited HfO 2as top-gate dielectric for ultrahigh photoresponsivity. NANOTECHNOLOGY 2021; 32:215203. [PMID: 33535194 DOI: 10.1088/1361-6528/abe2cc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
An asymmetric dual-gate (DG) MoS2field-effect transistor (FET) with ultrahigh electrical performance and optical responsivity using atomic-layer-deposited HfO2as a top-gate (TG) dielectric was fabricated and investigated. The effective DG modulation of the MoS2FET exhibited an outstanding electrical performance with a high on/off current ratio of 6 × 108. Furthermore, a large threshold voltage modulation could be obtained from -20.5 to -39.3 V as a function of the TG voltage in a DG MoS2phototransistor. Meanwhile, the optical properties were systematically explored under a series of gate biases and illuminated optical power under 550 nm laser illumination. An ultrahigh photoresponsivity of 2.04 × 105AW-1has been demonstrated with the structure of a DG MoS2phototransistor because the electric field formed by the DG can separate photogenerated electrons and holes efficiently. Thus, the DG design for 2D materials with ultrahigh photoresponsivity provides a promising opportunity for the application of optoelectronic devices.
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Zhao XF, Wen XH, Sun P, Zeng C, Liu MY, Yang F, Bi H, Li D, Ma RG, Wang JC, Yu XB, Zhang DW, Lu HL. Spider Web-like Flexible Tactile Sensor for Pressure-Strain Simultaneous Detection. ACS APPLIED MATERIALS & INTERFACES 2021; 13:10428-10436. [PMID: 33591176 DOI: 10.1021/acsami.0c21960] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Multiparameter integrated sensors are required for the next generation of flexible wearable electronics. However, mutual interference between detected signals is a technical bottleneck for a flexible tactile sensor to realize pressure-strain monitoring simultaneously and sensitively. Herein, a flexible dual-parameter pressure-strain sensor based on the three-dimensional (3D) tubular graphene sponge (TGS) and spider web-like stretchable electrodes is designed and fabricated. As the pressure-sensitive module, the unique 3D-TGS with an uninterrupted network of tubular graphene and high graphitic degree demonstrates great robust compressibility, supporting compression to ∼20% without shape collapse. The spider web-like stretchable electrodes as the strain-sensitive module are fabricated by a spray-embedded process based on the hierarchical multiscale hybrid nanocomposite of Ag nanowires (NWs) and carbon nanotubes (CNTs) with an optimal mass ratio. By comparing the output signals of spider web-like flexible electrodes, the magnitude and direction of the applied force can be effectively monitored simultaneously. Moreover, the potential applications of the flexible dual-parameter pressure-strain device in human-machine interaction are also explored, showing great promise in artificial intelligence and wearable systems.
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Tao JJ, Jiang J, Zhao SN, Zhang Y, Li XX, Fang X, Wang P, Hu W, Lee YH, Lu HL, Zhang DW. Fabrication of 1D Te/2D ReS 2 Mixed-Dimensional van der Waals p-n Heterojunction for High-Performance Phototransistor. ACS NANO 2021; 15:3241-3250. [PMID: 33544595 DOI: 10.1021/acsnano.0c09912] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The superior optical and electronic properties of the two-dimensional (2D) rhenium disulfide (ReS2) makes it suitable for nanoelectronic and optoelectronic applications. However, the internal defects coupled with with the low mobility and light-absorbing capability of ReS2 impede its utilization in high-performance photodetectors. Fabrication of mixed-dimensional heterojunctions is an alternative method for designing high-performance hybrid photodetectors. This study proposes a mixed-dimensional van der Waals (vdW) heterojunction photodetector, containing high-performance one-dimensional (1D) p-type tellurium (Te) and 2D n-type ReS2, developed by depositing Te nanowires on ReS2 nanoflake using the dry transfer method. It can improve the injection and separation efficiency of photoexcited electron-hole pairs due to the type II p-n heterojunction formed at the ReS2 and Te interface. The proposed heterojunction device is sensitive to visible-light sensitivity (632 nm) with an ultrafast photoresponse (5 ms), high responsivity (180 A/W), and specific detectivity (109), which is superior to the pristine Te and ReS2 photodetectors. As compared to the ReS2 device, the responsivity and response speed is better by an order of magnitude. These results demonstrate the fabrication and application potential of Te/ReS2 mixed-dimensional heterojunction for high-performance optoelectronic devices and sensors.
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Shi FX, Li P, Lu HL, Li N, Du QX, Wang YY, Sun JH. Expression of Autophagy-Associated Protein in Rat Muscle Tissues after Antemortem and Postmortem Injury. FA YI XUE ZA ZHI 2020; 36:293-298. [PMID: 32705839 DOI: 10.12116/j.issn.1004-5619.2020.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Indexed: 11/30/2022]
Abstract
Abstract Objective To study the expression of the three autophagy-associated proteins, BECN1, LC3 and p62, after the injury of the skeletal muscle of rats and to explore its application in differentiation between antemortem and postmortem injury. Methods The 72 healthy Sprague-Dawley rats were randomly divided into the undamaged control group, the antemortem injury group (0.5 h, 1 h, 2 h, 4 h, 8 h, 16 h and 24 h) and postmortem injury group (0.5 h, 1 h, 2 h and 4 h). A model of the injured right hind limb of rats was constructed. The expressions of the autophagy-associated proteins, BECN1, LC3-2/LC3-1 and p62, in the control group, the antemortem injury group and postmortem injury group were detected by Western blotting method. The data were respectively centralized and standardized and the orthogonal partial least square-discrimination analysis (OPLS-DA) identification model of antemortem and postmortem injury groups was constructed. Results The expression of BECN1, p62 protein and LC3-2/LC3-1 after the injury of the skeletal muscle of the rats showed different degrees of changes, but the differences among the 3 groups had no statistical significance. Antemortem and postmortem injury groups can be distinguished by centralizing and standardizing the expression levels of autophagy protein BECN1 and the ratio of LC3-2/LC3-1. The principal components extracted from OPLS-DA model of antemortem injury and postmortem injury had a relatively good interpretation of the model (Rx2=0.563, Ry2=0.439), but it were less predictive (Q2=0.366). Conclusion The expression of BECN1 and the ratio of LC3-2/LC3-1 in injured local tissue of the rat skeletal muscle can be used for the differentiation of antemortem injury group and postmortem injury group.
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Lu HL, Qu YF, Li H, Ji X. Contributions of source population and incubation temperature to phenotypic variation of hatchling Chinese skinks. Curr Zool 2020. [DOI: 10.1093/cz/zoaa063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Abstract
Phenotypic plasticity and local adaptation are viewed as the main factors that result in between-population variation in phenotypic traits, but contributions of these factors to phenotypic variation vary between traits and between species and have only been explored in a few species of reptiles. Here, we incubated eggs of the Chinese skink (Plestiodon chinensis) from 7 geographically separated populations in Southeast China at 3 constant temperatures (24, 28, and 32 °C) to evaluate the combined effects of clutch origin, source population, and incubation temperature on hatchling traits. The relative importance of these factors varied between traits. Nearly all examined hatchling traits, including body mass, snout–vent length (SVL), tail length, head size, limb length, tympanum diameter, and locomotor speed, varied among populations and were affected by incubation temperature. Measures for hatchling size (body mass and SVL) varied considerably among clutches. Source population explained much of the variation in hatchling body mass, whereas incubation temperature explained much of the variation in other examined traits. Our results indicate that between-population variation in hatchling traits of P. chinensis likely reflects the difference in natural incubation conditions and genetic divergence.
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Wang SH, Lu HL, Zhao MS, Zhou LM. [Assessing soil pH in Anhui Province based on different features mining methods combined with generalized boosted regression models]. YING YONG SHENG TAI XUE BAO = THE JOURNAL OF APPLIED ECOLOGY 2020; 31:3509-3517. [PMID: 33314841 DOI: 10.13287/j.1001-9332.202010.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We explored the application of different feature mining methods combined with genera-lized boosted regression models in digital soil mapping. Environmental covariates were selected by two feature selection methods i.e., recursive feature elimination and selection by filtering. Using the original environmental covariates and the selected optimal variable combination as independent varia-bles, soil pH prediction model of Anhui Province was established and mapped based on the genera-lized boosted regression model and random forest model. The results showed that both kinds of feature mining methods could effectively improve the accuracy of soil pH prediction by generalized boosted regression models and random forest model, and could reduce dimensionality. Compared with the random forest model, the prediction accuracy of the validation set of the generalized boosted regression model was slightly lower. In the training set, the accuracy of the generalized boosted regression models was much higher than that of the random forest model, with higher interpretation and better overall effect. The main parameters of the random forest model, ntree and mtry, had limi-ted effect on the model. Different parameters and their combination could affect the prediction accuracy of the generalized boosted regression models, and thus should be tuned before modeling. The results of spatial mapping showed that soil pH in Anhui Province showed a pattern of "south acid and north alkali".
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Chen JX, Li XX, Huang W, Ji ZG, Wu SZ, Xiao ZQ, Ou X, Zhang DW, Lu HL. High-energy x-ray radiation effects on the exfoliated quasi-two-dimensional β-Ga 2O 3 nanoflake field-effect transistors. NANOTECHNOLOGY 2020; 31:345206. [PMID: 32396888 DOI: 10.1088/1361-6528/ab925d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effects of x-ray irradiation on the mechanically exfoliated quasi-two-dimensional (quasi-2D) β-Ga2O3 nanoflake field-effect transistors (FETs) under the condition of biasing voltage were systematically investigated for the first time. It has been revealed that the device experienced two stages during irradiation. At low ionizing doses (<240 krad), the device performance is mainly influenced by the photo-effect and the subsequent persistent photocurrent (PPC) effect as a result of the pre-existing electron traps (e-trap) in the oxides far away from the SiO2/β-Ga2O3 interface. At larger doses (>240 krad), the device characteristics are dominated by the radiation-induced structural or compositional deterioration. The newly-generated e-traps are found located at the SiO2/β-Ga2O3 interface. This study shed light on the future radiation-tolerant device fabrication process development, paving a way towards the feasibility and practicability of β-Ga2O3-based devices in extreme-environment applications.
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Li X, Yang JG, Ma HP, Liu YH, Ji ZG, Huang W, Ou X, Zhang DW, Lu HL. Atomic Layer Deposition of Ga 2O 3/ZnO Composite Films for High-Performance Forming-Free Resistive Switching Memory. ACS APPLIED MATERIALS & INTERFACES 2020; 12:30538-30547. [PMID: 32539324 DOI: 10.1021/acsami.0c06476] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The resistive switching behavior in resistive random access memories (RRAMs) using atomic-layer-deposited Ga2O3/ZnO composite film as the dielectric was investigated. By alternatively atomic-layer-depositing Ga2O3 and ZnO with different thickness, we can accurately control the oxygen vacancy concentration. When regulating ZnO to ∼31%, the RRAMs exhibit a forming-free property as well as outstanding performance, including the ratio of a high resistance state to the low resistance state of 1000, retention time of more than 1 × 104 s, and the endurance of 100. By preparing RRAMs of different Zn concentration, we carried out a comparative study and explored the physical origin for the forming-free property as well as good performance. Finally, a unified model is proposed to account for the resistive switching and the current conduction mechanism, providing meaningful insights in the development of high-quality and forming-free RRAMs for future memory and neuromorphic applications.
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Tao JJ, Ma HP, Yuan KP, Gu Y, Lian JW, Li XX, Huang W, Nolan M, Lu HL, Zhang DW. Modification of 1D TiO 2 nanowires with GaO xN y by atomic layer deposition for TiO 2@GaO xN y core-shell nanowires with enhanced photoelectrochemical performance. NANOSCALE 2020; 12:7159-7173. [PMID: 32193525 DOI: 10.1039/c9nr10908k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
As a well-known semiconductor that can catalyse the oxygen evolution reaction, TiO2 has been extensively investigated for its solar photoelectrochemical water properties. Unmodified TiO2 shows some issues, particularly with respect to its photoelectrochemical performance. In this paper, we present a strategy for the controlled deposition of controlled amounts of GaOxNy cocatalysts on TiO2 1D nanowires (TiO2@GaOxNy core-shell) using atomic layer deposition. We show that this modification significantly enhances the photoelectrochemical performance compared to pure TiO2 NW photoanodes. For our most active TiO2@GaOxNy core-shell nanowires with a GaOxNy thickness of 20 nm, a photocurrent density up to 1.10 mA cm-2 (at 1.23 V vs. RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of unmodified TiO2 NWs. Furthermore, the band gap matching with TiO2 enhances the absorption of visible light over unmodified TiO2 and the facile oxygen vacancy formation after the deposition of GaOxNy also provides active sites for water activation. Density functional theory studies of model systems of GaOxNy-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaOxNy core-shell nanowires with ALD deposited GaOxNy demonstrate a good strategy for the fabrication of core-shell structures that enhance the photoelectrochemical performance of readily available photoanodes.
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Yuan K, Wang CY, Zhu LY, Cao Q, Yang JH, Li XX, Huang W, Wang YY, Lu HL, Zhang DW. Fabrication of a Micro-Electromechanical System-Based Acetone Gas Sensor Using CeO 2 Nanodot-Decorated WO 3 Nanowires. ACS APPLIED MATERIALS & INTERFACES 2020; 12:14095-14104. [PMID: 32096620 DOI: 10.1021/acsami.9b18863] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Preparation of reliable, stable, and highly responsive gas-sensing devices for the detection of acetone has been considered to be a key issue for the development of accurate disease diagnosis systems via exhaled breath. In this paper, novel CeO2 nanodot-decorated WO3 nanowires are successfully synthesized through a sequential hydrothermal and thermolysis process. Such CeO2 nanodot-decorated WO3 nanowires exhibited a remarkable enhancement in acetone-sensing performance based on a miniaturized micro-electromechanical system device, which affords high response (S = 1.30-500 ppb, 1.62-2.5 ppm), low detection limit (500 ppb), and superior selectivity toward acetone. The improved performance of the acetone sensor is likely to be originated from the fast carrier transportation of WO3 nanowires, the formation of WO3-CeO2 heterojunctions, and the existence of large amounts of oxygen vacancies in CeO2. The improved reaction thermodynamics and sensing mechanisms have also been revealed by the specific band alignment and X-ray photoelectron spectroscopy analysis.
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Zhao XF, Hang CZ, Wen XH, Liu MY, Zhang H, Yang F, Ma RG, Wang JC, Zhang DW, Lu HL. Ultrahigh-Sensitive Finlike Double-Sided E-Skin for Force Direction Detection. ACS APPLIED MATERIALS & INTERFACES 2020; 12:14136-14144. [PMID: 32131586 DOI: 10.1021/acsami.9b23110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Flexible pressure sensing is required for the excellent sensing performance and dexterous manipulation of the measured objects in their potential applications. Particularly, the ability to measure and discriminate the direction of force, contact surface, and contact location in real time is crucial for robotics with tactile feedback. Herein, a three-dimensional elastic porous carbon nanotube (CNT) sponge is synthesized by chemical vapor deposition, which is successfully applied in the piezoresistive sensor. In situ scanning electron microscopy study intuitively illustrates the characteristics that the microfibers of the CNT sponge distort and contact with each other under an external force. As a result, new conductive paths are created at the contact points between the CNT microfibers, which provides a basic sensing principle for a piezoresistive sensor. The CNT sponge-based sensor has an ultrahigh sensitivity in a wide pressure range (0-4 kPa for 4015.8 kPa-1), a rapid response time of 120 ms, and excellent durability over 5000 cycles. Moreover, a finlike flexible double-sided electronic skin (e-skin) is fabricated by a simple method to achieve force direction detection, which has potential applications in intelligent wearable devices and human-machine interaction.
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Chen JX, Li XX, Tao JJ, Cui HY, Huang W, Ji ZG, Sai QL, Xia CT, Lu HL, Zhang DW. Fabrication of a Nb-Doped β-Ga 2O 3 Nanobelt Field-Effect Transistor and Its Low-Temperature Behavior. ACS APPLIED MATERIALS & INTERFACES 2020; 12:8437-8445. [PMID: 32003210 DOI: 10.1021/acsami.9b20499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
For the first time, we report the successful fabrication of well-behaved field-effect transistors based on Nb-doped β-Ga2O3 nanobelts mechanically exfoliated from bulk single crystals. The exfoliated β-Ga2O3 nanobelts were transferred onto a purified surface of the 110 nm SiO2/Si substrate. These Nb-doped devices showed excellent electrical performance such as an ultrasmall cutoff current of ∼10 fA, a high current on/off ratio of >108, and a quite steep subthreshold swing (SS, ∼120 mV/decade). Furthermore, we investigated the temperature dependence down to 200 K, providing insightful information for its operation in a harsh environment. This work lays a foundation for wider application of Nb-doped β-Ga2O3 in nano-electronics.
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Yuan KP, Zhu LY, Yang JH, Hang CZ, Tao JJ, Ma HP, Jiang AQ, Zhang DW, Lu HL. Precise preparation of WO 3@SnO 2 core shell nanosheets for efficient NH 3 gas sensing. J Colloid Interface Sci 2020; 568:81-88. [PMID: 32088454 DOI: 10.1016/j.jcis.2020.02.042] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/10/2020] [Accepted: 02/12/2020] [Indexed: 12/23/2022]
Abstract
Development of high-performance ammonia (NH3) sensor is imperative for monitoring NH3 in the living environment. In this work, to obtain a high performance NH3 gas sensor, structurally well-defined WO3@SnO2 core shell nanosheets with a controllable thickness of SnO2 shell layer have been employed as sensing materials. The prepared core shell nanosheets were used to obtain a miniaturized gas sensor based on micro-electro-mechanical system (MEMS). By tuning the thickness of SnO2 layer via atomic layer deposition, a series of WO3@SnO2 core-shell nanosheets with tunable sensing properties were realized. Particularly, the sensor base on the fabricated WO3@SnO2 nanosheets with 20-nm SnO2 shell layer demonstrated superior gas sensing performance with the highest response (1.55) and selectivity toward 15 ppm NH3 at 200 °C. This remarkable enhancement of NH3 sensing ability could be ascribed to the formation of unique WO3-SnO2 core-shell heterojunction structure. The detailed mechanism was elucidated by the heterojunction-depletion model with the help of specific band alignment.
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Zhu LY, Yuan KP, Yang JH, Hang CZ, Ma HP, Ji XM, Devi A, Lu HL, Zhang DW. Hierarchical highly ordered SnO 2 nanobowl branched ZnO nanowires for ultrasensitive and selective hydrogen sulfide gas sensing. MICROSYSTEMS & NANOENGINEERING 2020; 6:30. [PMID: 34567644 PMCID: PMC8433378 DOI: 10.1038/s41378-020-0142-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/25/2019] [Accepted: 01/02/2020] [Indexed: 05/07/2023]
Abstract
Highly sensitive and selective hydrogen sulfide (H2S) sensors based on hierarchical highly ordered SnO2 nanobowl branched ZnO nanowires (NWs) were synthesized via a sequential process combining hard template processing, atomic-layer deposition, and hydrothermal processing. The hierarchical sensing materials were prepared in situ on microelectromechanical systems, which are expected to achieve high-performance gas sensors with superior sensitivity, long-term stability and repeatability, as well as low power consumption. Specifically, the hierarchical nanobowl SnO2@ZnO NW sensor displayed a high sensitivity of 6.24, a fast response and recovery speed (i.e., 14 s and 39 s, respectively), and an excellent selectivity when detecting 1 ppm H2S at 250 °C, whose rate of resistance change (i.e., 5.24) is 2.6 times higher than that of the pristine SnO2 nanobowl sensor. The improved sensing performance could be attributed to the increased specific surface area, the formation of heterojunctions and homojunctions, as well as the additional reaction between ZnO and H2S, which were confirmed by electrochemical characterization and band alignment analysis. Moreover, the well-structured hierarchical sensors maintained stable performance after a month, suggesting excellent stability and repeatability. In summary, such well-designed hierarchical highly ordered nanobowl SnO2@ZnO NW gas sensors demonstrate favorable potential for enhanced sensitive and selective H2S detection with long-term stability and repeatability.
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Ou XL, Lu HL, Shen J, Qu N, Liang H. Calculation of Likelihood Ratio for Identifying Half Sibling Relationship When Both Biological Mothers Participate. FA YI XUE ZA ZHI 2019; 35:662-666. [PMID: 31970951 DOI: 10.12116/j.issn.1004-5619.2019.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Indexed: 06/10/2023]
Abstract
Objective To derive the formulae for likelihood ratio (LR) calculation of half sibling relationships when both mothers participate. Methods Based on the fact that both biological mothers participate in the identification of half sibling relationship between the two individuals, test hypothesis for the identification of half sibling relationship was established. Conditional probability ratios of genetic evidence under null hypothesis and alternative hypothesis conditions were simplified, and then applied to a real case of half sibling relationship identification. At the same time, the LR of half sibling relationships under the assumption that only a single biological mother or none of the biological mothers participate were respectively calculated. Results In the cases of identification of half sibling relationship from same fathers, with no biological father involved, after the same genetic indicator test analysis, when both biological mothers participate in the identification, the accumulated LR value was higher than that of accumulated LR with only a single biological mother or no parents participating. Conclusion When the autosome STR test is used for the identification and analysis of half sibling relationship between two individuals, the calculation of LR is more simple, intuitive and operable with both mothers participating. The biological mothers should participate in the test as much as possible, otherwise the number of STR loci would need to be increased for a more specific conclusion.
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Chen JX, Li XX, Ma HP, Huang W, Ji ZG, Xia C, Lu HL, Zhang DW. Investigation of the Mechanism for Ohmic Contact Formation in Ti/Al/Ni/Au Contacts to β-Ga 2O 3 Nanobelt Field-Effect Transistors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:32127-32134. [PMID: 31403281 DOI: 10.1021/acsami.9b09166] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The issue of contacts between the electrode and channel layer is crucial for wide-bandgap semiconductors, especially the β-Ga2O3 due to its ultra-large bandgap (4.6-4.9 eV). It affects the device performance greatly and thus needs special attention. In this work, the high-performance β-Ga2O3 nanobelt field-effect transistors with Ohmic contact between multilayer metal stack Ti/Al/Ni/Au (30/120/50/50 nm) and unintentionally doped β-Ga2O3 channel substrate have been fabricated. The formation mechanism of Ohmic contacts to β-Ga2O3 under different annealing temperatures in an N2 ambient is systematically investigated by X-ray photoelectron spectroscopy. It is revealed that the oxygen vacancies at the interface of β-Ga2O3/intermetallic compounds formed during rapid thermal annealing are believed to induce the good Ohmic contacts with low resistance. The contact resistance (Rc) between electrodes and unintentionally doped β-Ga2O3 reduces to ∼9.3 Ω mm after annealing. This work points to the importance of contact engineering for future improved β-Ga2O3 device performance and lays a solid foundation for the wider application of β-Ga2O3 in electronics and optoelectronics.
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Liu QQ, Guo HM, Wang L, Lu HL, Du QX, Bai RF, Sun JH, Wang YY. Wound Age Estimation by Neutrophil Migration Distance. FA YI XUE ZA ZHI 2019; 35:166-170. [PMID: 31135110 DOI: 10.12116/j.issn.1004-5619.2019.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Indexed: 11/30/2022]
Abstract
Abstract Objective To explore the application of neutrophil migration distance for wound age estimation of skeletal muscles in rats, and to provide methodological basis for follow-up study in future. Methods The skeletal muscle contusion model was established in rats, and the control group and the 2, 4, 6 h post-traumatic groups were set. The law of response of neutrophils that participated in the inflammation after injury was detected by immunohistochemical staining, and the relationship between neutrophil migration distance and injury time was detected by TissueFAXS PLUS software. Results The skeletal muscle was obviously infiltrated with neutrophils 2-6 h after injury. The positive rate of neutrophil was (28.75±0.94)% at 2 h post-traumatic, and reached the peak (45.50±3.63)% at 4 h post-traumatic, then decreased to (31.92±1.56)% at 6 h post-traumatic. The neutrophil migration distances increased with the progress of inflammation, and reached (124.80±12.32) μm, (229.03±21.45) μm and (335.04±16.75) μm at 2 h, 4 h and 6 h, respectively. Conclusion There is a relationship of neutrophil infiltrated number and migration distance and wound age within the 2-6 h after skeletal muscle injury, which could be used for the inference of skeletal muscle wound age.
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