The Experts below are selected from a list of 1215 Experts worldwide ranked by ideXlab platform
Yue Li - One of the best experts on this subject based on the ideXlab platform.
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Physical Deposition improved sers stability of morphology controlled periodic micro nanostructured arrays based on colloidal templates
Small, 2015Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:: An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10(-11) M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
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Physical Deposition Improved SERS Stability of Morphology Controlled Periodic Micro/Nanostructured Arrays Based on Colloidal Templates
Small, 2014Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10−11 M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
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Physical Deposition Assisted Colloidal Lithography: A Technique to Ordered Micro/Nanostructured Arrays
Advances in Unconventional Lithography, 2011Co-Authors: Yue Li, Guotao Duan, Naoto KoshizakiAbstract:Ordered micro/nanostructured arrays have attracted much interest due to their important applications in microfluidic devices, optoelectronic devices, nanophotonics, field emitters, nanogenerators, sensors, nano-biotechnology, surface science, photocatalytic properties etc.111 The traditional routes to create periodic micro/nanostructured arrays are generally divided into two step. Microsized structure arrays are first fabricated by traditional lithographic techniques (e.g. photo-lithography, electron-beam lithography, ion beam lithography, x-ray lithography)12-15. as well as soft lithography (e.g. the techniques of replica molding, microcontact printing, micromolding in capillaries)16-19, the nanostructures are then modified on the microsized units in array,20 thus hierarchical micro/nanostructured arrays are finally achieved. However, they cannot be afforded due to the high costs and time-consuming in the most laboratories. Recently, the monolayered colloidal crystals (or called colloidal monolayers), ordered monolayer colloidal sphere arrays with hexagonal close-packed lattice structures on a certain substrate by self-assembly,21-35 can be used to prepare ordered structure arrays. 36-41 It has proved that it is a flexible approach to fabricate the periodic micro or nanostructure arrays (e.g. nanoparticle arrays,42-49. nanopore arrays,50-59 hollow sphere arrays60-65) based on colloidal monolayer templates by the different routes, solution/sol-dipping route, electrochemical Deposition etc. Their properties are morphology and arrangement parameter dependent. Besides these periodic structure arrays, the colloidal monolayer template also can be used to prepare hierarchical micro/nanostructured arrays. For example, the hierarchical micro/nanostructured polystyrene (PS) sphere/CNTs composite arrays were obtained by wet chemical self assembling;66-68 hierarchical microsized PS sphere/silver nanoparticle composite arrays or microsized pore/silver nanoparticle arrays were made by thermal Deposition of silver precursor;69,70 gold hierarchical micro/nanostructured particle arrays were created by electrochemical Deposition based two step replication of colloidal monolayer template.71 However, these routes have been
Honghua Zhang - One of the best experts on this subject based on the ideXlab platform.
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Physical Deposition improved sers stability of morphology controlled periodic micro nanostructured arrays based on colloidal templates
Small, 2015Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:: An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10(-11) M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
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Physical Deposition Improved SERS Stability of Morphology Controlled Periodic Micro/Nanostructured Arrays Based on Colloidal Templates
Small, 2014Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10−11 M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
H R Shahverdi - One of the best experts on this subject based on the ideXlab platform.
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new Physical Deposition approach for low cost inorganic hole transport layer in normal architecture of durable perovskite solar cells
ACS Applied Materials & Interfaces, 2015Co-Authors: Bahram Abdollahi Nejand, Vahid Ahmadi, H R ShahverdiAbstract:In this work we reported sputter deposited NiOx/Ni double layer as an HTM/contact couple in normal architecture of perovskite solar cell. A perovskite solar cell that is durable for more than 60 days was achieved, with increasing efficiency from 1.3% to 7.28% within 6 days. Moreover, low temperature direct Deposition of NiOx layer on perovskite layer was introduced as a potential hole transport material for an efficient cost-effective solar cell applicable for various morphologies of perovskite layers, even for perovskite layers containing pinholes, which is a notable challenge in perovskite solar cells. The angular Deposition of NiOx layers by dc reactive magnetron sputtering showed uniform and crack-free coverage of the perovskite layer with no negative impact on perovskite structure that is suitable for nickel back contact layer, surface shielding against moisture, and mechanical damages. Replacing the expensive complex materials in previous perovskite solar cells with low cost available materials intr...
Bahram Abdollahi Nejand - One of the best experts on this subject based on the ideXlab platform.
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Two-Step Physical Deposition of a Compact CuI Hole-Transport Layer and the Formation of an Interfacial Species in Perovskite Solar Cells
Chemsuschem, 2016Co-Authors: Saba Gharibzadeh, Bahram Abdollahi Nejand, Vahid Ahmadi, Ahmad Moshaii, Nasim Mohammadian, Amir Hossein Alizadeh, Rahele Mohammadpour, Abdolali AlizadehAbstract:A simple and practical approach is introduced for the Deposition of CuI as an inexpensive inorganic hole-transport material (HTM) for the fabrication of low cost perovskite solar cells (PSCs) by gas–solid phase transformation of Cu to CuI. The method provides a uniform and well-controlled CuI layer with large grains and good compactness that prevents the direct connection between the contact electrodes. Solar cells prepared with CuI as the HTM with Au electrodes displays an exceptionally high short-circuit current density of 32 mA cm−2, owing to an interfacial species formed between the perovskite and the Cu resulting in a long wavelength contribution to the incident photon-to-electron conversion efficiency (IPCE), and an overall power conversion efficiency (PCE) of 7.4 %. The growth of crystalline and uniform CuI on a low roughness perovskite layer leads to remarkably high charge extraction in the cells, which originates from the high hole mobility of CuI in addition to a large number of contact points between CuI and the perovskite layer. In addition, the solvent-free method has no damaging side effect on the perovskite layer, which makes it an appropriate method for large scale applications of CuI in perovskite solar cells.
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new Physical Deposition approach for low cost inorganic hole transport layer in normal architecture of durable perovskite solar cells
ACS Applied Materials & Interfaces, 2015Co-Authors: Bahram Abdollahi Nejand, Vahid Ahmadi, H R ShahverdiAbstract:In this work we reported sputter deposited NiOx/Ni double layer as an HTM/contact couple in normal architecture of perovskite solar cell. A perovskite solar cell that is durable for more than 60 days was achieved, with increasing efficiency from 1.3% to 7.28% within 6 days. Moreover, low temperature direct Deposition of NiOx layer on perovskite layer was introduced as a potential hole transport material for an efficient cost-effective solar cell applicable for various morphologies of perovskite layers, even for perovskite layers containing pinholes, which is a notable challenge in perovskite solar cells. The angular Deposition of NiOx layers by dc reactive magnetron sputtering showed uniform and crack-free coverage of the perovskite layer with no negative impact on perovskite structure that is suitable for nickel back contact layer, surface shielding against moisture, and mechanical damages. Replacing the expensive complex materials in previous perovskite solar cells with low cost available materials intr...
Guotao Duan - One of the best experts on this subject based on the ideXlab platform.
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Physical Deposition improved sers stability of morphology controlled periodic micro nanostructured arrays based on colloidal templates
Small, 2015Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:: An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10(-11) M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
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Physical Deposition Improved SERS Stability of Morphology Controlled Periodic Micro/Nanostructured Arrays Based on Colloidal Templates
Small, 2014Co-Authors: Honghua Zhang, Fei Zhou, Guotao Duan, Yue LiAbstract:An effective and inexpensive method is developed to fabricate periodic arrays by sacrificial colloidal monolayer template route by chemical Deposition and further Physical Deposition. By a colloidal template induced precursor solution dipping strategy, different periodic arrays of semi-hollow sphere array, inverse opal with monolayer pore arrays and hole arrays are obtained under different conditions. After magnetron sputtering Deposition, their morphologies are changed to novel micro/nanostructured arrays of honeycomb-shaped arrays, hollow cavity arrays, and regular network arrays due to multiple direction Deposition of sputtering Deposition and shadow effect. After coating a gold thin layer, these periodic micro/nanostructured arrays are used as SERS active substrates and demonstrate a very stable SERS performance compared with periodic arrays achieved by direct colloidal template-induced chemical Deposition. Additionally, a honeycomb-shaped array displays better SERS enhancement than that of a hollow cavity array or a regular network array. After optimization of honeycomb-shaped arrays with different periodicities, an array with periodicity of 350 nm demonstrates much stronger SERS enhancement and possesses a low detection limit of 10−11 M R6G. Such stable SERS performance is useful for practical application in portable Raman detecting devices to detect organic molecules.
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Physical Deposition Assisted Colloidal Lithography: A Technique to Ordered Micro/Nanostructured Arrays
Advances in Unconventional Lithography, 2011Co-Authors: Yue Li, Guotao Duan, Naoto KoshizakiAbstract:Ordered micro/nanostructured arrays have attracted much interest due to their important applications in microfluidic devices, optoelectronic devices, nanophotonics, field emitters, nanogenerators, sensors, nano-biotechnology, surface science, photocatalytic properties etc.111 The traditional routes to create periodic micro/nanostructured arrays are generally divided into two step. Microsized structure arrays are first fabricated by traditional lithographic techniques (e.g. photo-lithography, electron-beam lithography, ion beam lithography, x-ray lithography)12-15. as well as soft lithography (e.g. the techniques of replica molding, microcontact printing, micromolding in capillaries)16-19, the nanostructures are then modified on the microsized units in array,20 thus hierarchical micro/nanostructured arrays are finally achieved. However, they cannot be afforded due to the high costs and time-consuming in the most laboratories. Recently, the monolayered colloidal crystals (or called colloidal monolayers), ordered monolayer colloidal sphere arrays with hexagonal close-packed lattice structures on a certain substrate by self-assembly,21-35 can be used to prepare ordered structure arrays. 36-41 It has proved that it is a flexible approach to fabricate the periodic micro or nanostructure arrays (e.g. nanoparticle arrays,42-49. nanopore arrays,50-59 hollow sphere arrays60-65) based on colloidal monolayer templates by the different routes, solution/sol-dipping route, electrochemical Deposition etc. Their properties are morphology and arrangement parameter dependent. Besides these periodic structure arrays, the colloidal monolayer template also can be used to prepare hierarchical micro/nanostructured arrays. For example, the hierarchical micro/nanostructured polystyrene (PS) sphere/CNTs composite arrays were obtained by wet chemical self assembling;66-68 hierarchical microsized PS sphere/silver nanoparticle composite arrays or microsized pore/silver nanoparticle arrays were made by thermal Deposition of silver precursor;69,70 gold hierarchical micro/nanostructured particle arrays were created by electrochemical Deposition based two step replication of colloidal monolayer template.71 However, these routes have been