Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu na...Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu nanoparticles(Cu@Ag NPs)paste can execute bonding with high quality at 250℃,and the achieved supersaturated Ag-Cu nanoalloy joint with ultrahigh shear strength(152 MPa)dramatically exceeds most nano-paste joints.The interstitial solid solutions with atomic-level metallurgical bonds at the interface dominantly promoted the shear strength.Besides,the numerous ultrafine nanograin,high proportion of low angle grain boundaries(7.44%)without deformation,and the Cu nanoprecipitates in the joint would improve subordinately.Furthermore,the high content(16.8%)of∑3 twin boundaries would contribute to the electrical and thermal conductivity.Thus,the multiple strengthening mechanisms with the solid solution,the second precipitated phase,and ultrafine nanograin can dramatically enhance shear strength and electro-thermal conductivity of joints for high-temperature device packaging.展开更多
The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we re...The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we report a high-performanee dual-channel phototransistor based on one-dimensional (1D)/two-dimensional (2D) trigonal selenium (t-Se)/ReS2 heterostructures grown by chemical vapor deposition. The injection and separati on efficie ncy of photoge nerated electro n-hole pairs can be greatly improved due to the high-quality in terfacial con tact betwee n t-Se nano belts and ReS2 films. Compared with bare ReS2 film devices, the dual-cha nnel phototra nsistor based on t-Se/ReS2 heterostructure exhibits considerable enhancement with the responsivity (R) and detectivity (D^*) up to 98 A·W^-1 and 6 x 10^10 Jones at 400 nm illumination with an in tensity of 1.7 mW·cm^-2, respectively. Besides, the respo nse time can also be reduced by three times of magnitude to less than 50 ms due to the type-11 band alignment at the in terface. This study opens up a promising ave nue for high-performa nee photodetectors by constructing mixed-dimensional heterostructures.展开更多
Developing dual-state luminophores(DSLs)with strong fluorescence in both the monomer and aggregate states is urgently needed but remains a huge challenge because most current luminophores are either aggregation-induce...Developing dual-state luminophores(DSLs)with strong fluorescence in both the monomer and aggregate states is urgently needed but remains a huge challenge because most current luminophores are either aggregation-induced emission or aggregation-caused quenching molecules.Moreover,limited by the structural conservation of the few existing DSLs,there are not enough response sites that can be used to customize various activatable fluorescent probes for specific molecular imaging.Herein,we engineered a general integration strategy for the fabrication of such DSLs with excellent photophysical properties.The DSLs,with their tunable spectra,a large Stokes shift(>170 nm),and achievable near-infrared(NIR)emission,show great potential for high-contrast imaging.Importantly,DSLs can be used as a universal platform for probe customization due to their activatable fluorescence through protection-deprotection of the phenolic hydroxyl group.Based on this,an NIR fluorescent probe DSL-Gal was developed for sensing of β-galactosidase in solutions,senescent cells,and liver metastases with high contrast,further confirming the superiority and universal feasibility of DSLs in probe design.The integration strategy may provide a novel approach for the generation of other DSLs and have great potential applications in bioimaging.展开更多
Photoacoustic imaging(PAI) is a non-destructive biomedical imaging technology with broad application prospects. PAI combines the advantages of optical imaging and ultrasound imaging with high selectivity and deep pene...Photoacoustic imaging(PAI) is a non-destructive biomedical imaging technology with broad application prospects. PAI combines the advantages of optical imaging and ultrasound imaging with high selectivity and deep penetration to overcome the high scattering limitation of light in tissues. This emerging technology also achieves high-resolution and high-contrast imaging of deep tissue in vivo. Recently, photoacoustic(PA) probes based on organic dyes have emerged prominently in biosensing and bioimaging due to their excellent optical properties and structural adaptability. This paper gives an outline of the basic PAI principles and focuses on the application of organic-dye-based PA probes for molecular detection and in vivo imaging. The advantages of PAI technology and the drawbacks of current PA probes are then summarized. Finally, the prospects for application are evaluated considering the potential challenges in the biomedical fields.展开更多
基金This work was financially supported by the National Natu-ral Science Foundation of China(No.NSFC 51775140)A part of the work was also supported by the National Science and Technology Major Project(No.2017-VI-0009-0080)+2 种基金the Guangdong Province key research and development program(No.2019B010935001)the Shenzhen Science and Technology Plan(No.JCYJ20180507183511908)Bureau of Industry and Information Technology of Shenzhen through the Innovation Chain and Industry Chain(No.201806071354163490).
文摘Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu nanoparticles(Cu@Ag NPs)paste can execute bonding with high quality at 250℃,and the achieved supersaturated Ag-Cu nanoalloy joint with ultrahigh shear strength(152 MPa)dramatically exceeds most nano-paste joints.The interstitial solid solutions with atomic-level metallurgical bonds at the interface dominantly promoted the shear strength.Besides,the numerous ultrafine nanograin,high proportion of low angle grain boundaries(7.44%)without deformation,and the Cu nanoprecipitates in the joint would improve subordinately.Furthermore,the high content(16.8%)of∑3 twin boundaries would contribute to the electrical and thermal conductivity.Thus,the multiple strengthening mechanisms with the solid solution,the second precipitated phase,and ultrafine nanograin can dramatically enhance shear strength and electro-thermal conductivity of joints for high-temperature device packaging.
基金National Natural Science Foundation of China (Nos. 51572057 and 51772064)AFOSR/NSF EFRI 2DARE program, ARO and SRC.
文摘The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we report a high-performanee dual-channel phototransistor based on one-dimensional (1D)/two-dimensional (2D) trigonal selenium (t-Se)/ReS2 heterostructures grown by chemical vapor deposition. The injection and separati on efficie ncy of photoge nerated electro n-hole pairs can be greatly improved due to the high-quality in terfacial con tact betwee n t-Se nano belts and ReS2 films. Compared with bare ReS2 film devices, the dual-cha nnel phototra nsistor based on t-Se/ReS2 heterostructure exhibits considerable enhancement with the responsivity (R) and detectivity (D^*) up to 98 A·W^-1 and 6 x 10^10 Jones at 400 nm illumination with an in tensity of 1.7 mW·cm^-2, respectively. Besides, the respo nse time can also be reduced by three times of magnitude to less than 50 ms due to the type-11 band alignment at the in terface. This study opens up a promising ave nue for high-performa nee photodetectors by constructing mixed-dimensional heterostructures.
基金the generous financial support of the National Key R&D Program of China(grant no.2019YFA0210100)the National Natural Science Foundation of China(grant nos.21890744 and 21877029)+1 种基金the Hunan Postgraduate Research and Innovation Project(grant no.CX2018B187)the China Postdoctoral Science Foundation(grant nos.2019TQ0085 and 2020M682538).
文摘Developing dual-state luminophores(DSLs)with strong fluorescence in both the monomer and aggregate states is urgently needed but remains a huge challenge because most current luminophores are either aggregation-induced emission or aggregation-caused quenching molecules.Moreover,limited by the structural conservation of the few existing DSLs,there are not enough response sites that can be used to customize various activatable fluorescent probes for specific molecular imaging.Herein,we engineered a general integration strategy for the fabrication of such DSLs with excellent photophysical properties.The DSLs,with their tunable spectra,a large Stokes shift(>170 nm),and achievable near-infrared(NIR)emission,show great potential for high-contrast imaging.Importantly,DSLs can be used as a universal platform for probe customization due to their activatable fluorescence through protection-deprotection of the phenolic hydroxyl group.Based on this,an NIR fluorescent probe DSL-Gal was developed for sensing of β-galactosidase in solutions,senescent cells,and liver metastases with high contrast,further confirming the superiority and universal feasibility of DSLs in probe design.The integration strategy may provide a novel approach for the generation of other DSLs and have great potential applications in bioimaging.
基金supported by the National Natural Science Foundation of China (21890744)the Science and Technology Project of Hunan Province (2016WK2002, 2016RS2009)
文摘Photoacoustic imaging(PAI) is a non-destructive biomedical imaging technology with broad application prospects. PAI combines the advantages of optical imaging and ultrasound imaging with high selectivity and deep penetration to overcome the high scattering limitation of light in tissues. This emerging technology also achieves high-resolution and high-contrast imaging of deep tissue in vivo. Recently, photoacoustic(PA) probes based on organic dyes have emerged prominently in biosensing and bioimaging due to their excellent optical properties and structural adaptability. This paper gives an outline of the basic PAI principles and focuses on the application of organic-dye-based PA probes for molecular detection and in vivo imaging. The advantages of PAI technology and the drawbacks of current PA probes are then summarized. Finally, the prospects for application are evaluated considering the potential challenges in the biomedical fields.