A recent progress in new emerging two-dimensional(2 D)materials has provided promising opportunity for gas sensing in ultra-low detectable concentration.In this work,we have demonstrated a flexible NO2 gas sensor with...A recent progress in new emerging two-dimensional(2 D)materials has provided promising opportunity for gas sensing in ultra-low detectable concentration.In this work,we have demonstrated a flexible NO2 gas sensor with porous structure graphene on polyethylene terephthalate substrates operating at room temperature.The gas sensor exhibited good performance with response of 1.2%and a fast response time within 30 s after exposure to50×10^-9 NO2 gas.As porous structure of graphene increased the surface area,the sensor showed high sensitivity of ppb level for NO2 detection.Au nanoparticles were decorated on the surface of the porous structure graphene skeleton,resulting in an incensement of response compared with pristine graphene.Au nanoparticles-decorated graphene exhibits not only better sensitivity(1.5-1.6 times larger than pristine graphene)for NO2 gas detection,but also fast response.The sensor was found to be robust and sensitive under the cycling bending test,which could also be ascribed to the merits of graphene.This porous structure graphene-based gas sensor is expected to enable a simple and inexpensive flexible gas sensing platform.展开更多
Biomedical materials have received increasing attention in recent decades and have been used in medical applications to advance patient care,such as prosthetic implants,tissue repair and regeneration,drug delivery sys...Biomedical materials have received increasing attention in recent decades and have been used in medical applications to advance patient care,such as prosthetic implants,tissue repair and regeneration,drug delivery systems,pharmaceutical or biological therapy products,and sensitive diagnostic technologies.Among different types of biomedical materials,nonferrous metals and related materials(NMRMs)are important and attractive candidates.The updating of biomedical NMRMs and devices heavily relies on original research and applicationoriented innovation.Here,we provide recent research findings and succinct insights into the developments in NMRMs for biomedical applications in China,including the use of titanium,magnesium,copper,zinc,cobalt,zirconium,hafnium,niobium,rhenium,tantalum,tungsten,silver,gold,platinum,palladium,their alloys and compounds,rare earths,high-entropy alloys,and liquid metals.Finally,the literature review concludes with several possible directions of NMRMs for new and future developments in biomedical engineering.展开更多
This paper introduces a feasible process to achieve the molybdenum disulfide atomic layers using chemical vapor deposition(CVD) method,with molybdenum thin film and solid sulfur as precursors.And some improvements wer...This paper introduces a feasible process to achieve the molybdenum disulfide atomic layers using chemical vapor deposition(CVD) method,with molybdenum thin film and solid sulfur as precursors.And some improvements were made to reduce the amount of metastable MoS_(2)-3 R.The morphology of the acquired MoS_(2) layers,existing as triangular flakes or large-area continuous films,can be controlled by adjusting the synthesis time and reacting temperature.The characterization results show that the monolayer MoS_(2) flakes reveal a(002)-oriented growth on SiO_(2)/Si substrates,and its crystalline domain size is approximately 30 μm,and the thickness is 0.65 nm.Since the synthesis of MoS_(2)-3 R is restrained,the electronic transport properties of MoS_(2) with different layers were investigated,revealing that those properties equal with those of MoS_(2) samples prepared by exfoliation methods.展开更多
Resistive switching (RS) behaviors of Dy2O3- based memory devices with and without Pt nanocrystals (Pt-nc) layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excelle...Resistive switching (RS) behaviors of Dy2O3- based memory devices with and without Pt nanocrystals (Pt-nc) layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excellent unipolar RS characteristics, including highly uniform switching parameters, lower switching voltage (〈1.2 V), high resistance ratio (〉1 × 104), a large number of switching cycles, as well as long retention time (〉1 × 105 s), owing to the local electric field confined and strengthened near the nanocrystals' location.展开更多
The band alignment of HfO2 film on p-type (100) InP substrate grown by magnetron sputtering was investigated.The chemical states and bonding characteristics of the system were characterized by X-ray photoelectron sp...The band alignment of HfO2 film on p-type (100) InP substrate grown by magnetron sputtering was investigated.The chemical states and bonding characteristics of the system were characterized by X-ray photoelectron spectroscopy (XPS).The results show that there is no existence of Hf-P or Hf-In and there are interfacial In2O3 and InPO4 at the interface.Ultraviolet spectrophotometer (UVS) was employed to obtain the band gap value of HfO2.In 3d and Hf 4f core-level spectra and valence spectra were employed to obtain the valence band offset of HfO2/InP.Experimental results show that the (5.88 ± 0.05) eV band gap of HfO2 is aligned to the band gap of InP with a conduction band offset (△Ec) of (2.74 ± 0.05) eV and a valence band offset (△Ev) of (1.80 ± 0.05) eV.Compared with HfO2 on Si,HfO2 on InP exhibits a much larger conduction band offset (1.35 eV larger),which is beneficial to suppress the tunneling leakage current.展开更多
基金financially supported by National Natural Science Foundation of China(No.61874137)。
文摘A recent progress in new emerging two-dimensional(2 D)materials has provided promising opportunity for gas sensing in ultra-low detectable concentration.In this work,we have demonstrated a flexible NO2 gas sensor with porous structure graphene on polyethylene terephthalate substrates operating at room temperature.The gas sensor exhibited good performance with response of 1.2%and a fast response time within 30 s after exposure to50×10^-9 NO2 gas.As porous structure of graphene increased the surface area,the sensor showed high sensitivity of ppb level for NO2 detection.Au nanoparticles were decorated on the surface of the porous structure graphene skeleton,resulting in an incensement of response compared with pristine graphene.Au nanoparticles-decorated graphene exhibits not only better sensitivity(1.5-1.6 times larger than pristine graphene)for NO2 gas detection,but also fast response.The sensor was found to be robust and sensitive under the cycling bending test,which could also be ascribed to the merits of graphene.This porous structure graphene-based gas sensor is expected to enable a simple and inexpensive flexible gas sensing platform.
基金the Chinese Academy of Engineering (Nos. 2019-ZD-25-04, 2019-ZD31-03, 2019-ZD-27-03, 2020-JJZD-1 and 2021-HYZD-6)。
文摘Biomedical materials have received increasing attention in recent decades and have been used in medical applications to advance patient care,such as prosthetic implants,tissue repair and regeneration,drug delivery systems,pharmaceutical or biological therapy products,and sensitive diagnostic technologies.Among different types of biomedical materials,nonferrous metals and related materials(NMRMs)are important and attractive candidates.The updating of biomedical NMRMs and devices heavily relies on original research and applicationoriented innovation.Here,we provide recent research findings and succinct insights into the developments in NMRMs for biomedical applications in China,including the use of titanium,magnesium,copper,zinc,cobalt,zirconium,hafnium,niobium,rhenium,tantalum,tungsten,silver,gold,platinum,palladium,their alloys and compounds,rare earths,high-entropy alloys,and liquid metals.Finally,the literature review concludes with several possible directions of NMRMs for new and future developments in biomedical engineering.
基金financially supported by the National Natural Science Foundation of China (Nos.50835002 and 51105102)。
文摘This paper introduces a feasible process to achieve the molybdenum disulfide atomic layers using chemical vapor deposition(CVD) method,with molybdenum thin film and solid sulfur as precursors.And some improvements were made to reduce the amount of metastable MoS_(2)-3 R.The morphology of the acquired MoS_(2) layers,existing as triangular flakes or large-area continuous films,can be controlled by adjusting the synthesis time and reacting temperature.The characterization results show that the monolayer MoS_(2) flakes reveal a(002)-oriented growth on SiO_(2)/Si substrates,and its crystalline domain size is approximately 30 μm,and the thickness is 0.65 nm.Since the synthesis of MoS_(2)-3 R is restrained,the electronic transport properties of MoS_(2) with different layers were investigated,revealing that those properties equal with those of MoS_(2) samples prepared by exfoliation methods.
基金financially supported by the National Natural Science Foundation of China(Nos.50932001,51102020,and 51202013)the Important National Science&Technology Specific Projects(No.2009ZX02039-005)
文摘Resistive switching (RS) behaviors of Dy2O3- based memory devices with and without Pt nanocrystals (Pt-nc) layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excellent unipolar RS characteristics, including highly uniform switching parameters, lower switching voltage (〈1.2 V), high resistance ratio (〉1 × 104), a large number of switching cycles, as well as long retention time (〉1 × 105 s), owing to the local electric field confined and strengthened near the nanocrystals' location.
基金financially supported by the National Natural Science Foundation of China(Nos.50932001,51102020,and 51202013)
文摘The band alignment of HfO2 film on p-type (100) InP substrate grown by magnetron sputtering was investigated.The chemical states and bonding characteristics of the system were characterized by X-ray photoelectron spectroscopy (XPS).The results show that there is no existence of Hf-P or Hf-In and there are interfacial In2O3 and InPO4 at the interface.Ultraviolet spectrophotometer (UVS) was employed to obtain the band gap value of HfO2.In 3d and Hf 4f core-level spectra and valence spectra were employed to obtain the valence band offset of HfO2/InP.Experimental results show that the (5.88 ± 0.05) eV band gap of HfO2 is aligned to the band gap of InP with a conduction band offset (△Ec) of (2.74 ± 0.05) eV and a valence band offset (△Ev) of (1.80 ± 0.05) eV.Compared with HfO2 on Si,HfO2 on InP exhibits a much larger conduction band offset (1.35 eV larger),which is beneficial to suppress the tunneling leakage current.