Fluorescent Logic Gates Chemically Attached to Silicon Nanowires

2009 ◽  
Vol 121 (19) ◽  
pp. 3521-3524 ◽  
Author(s):  
Lixuan Mu ◽  
Wensheng Shi ◽  
Guangwei She ◽  
Jack C. Chang ◽  
Shuit-Tong Lee
Nano Letters ◽  
2012 ◽  
Vol 12 (6) ◽  
pp. 3074-3079 ◽  
Author(s):  
Massimo Mongillo ◽  
Panayotis Spathis ◽  
Georgios Katsaros ◽  
Pascal Gentile ◽  
Silvano De Franceschi

2005 ◽  
Vol 879 ◽  
Author(s):  
Rezina Siddique ◽  
George Sirinakis ◽  
Michael A. Carpenter

AbstractSilicon Nanowires (SiNWs) have many potential applications that include diodes, transistors, logic gates, circuitry, and sensors. SiNWs also open the possibility for integrating optoelectronics with microelectronics, since silicon has semiconducting properties and amorphous silicon nanowires have been shown to emit blue light. It has been demonstrated that SiNWs have tunable electrical properties, depending on the dopant used. With such a range of applications, the ability to mass-produce silicon nanowires simply and easily with no other source of silicon needed other than the substrate itself will prove very useful. Such methods have previously been reported, but our method involves production of the SiNWs at a lower temperature than those widely observed. A (100) silicon substrate was cleaned for five minutes each in ethanol followed by acetone. Films with thicknesses of less than 20 nm of either gold or 60/40 gold/palladium were deposited on the substrate through physical vapor deposition to serve as the growth center for the SiNWs. The samples were placed in a furnace and annealed to 900° C, under a 1500 sccm flow of argon at atmospheric pressure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for characterization of the SiNWs. The resulting SiNWs were amorphous in structure and very convoluted, with lengths on the order of tens of microns, diameters of 40 nm and a bed thickness of approximately 10 m. The effect of varying gold concentration, annealing time, temperature, and gas flow rate were then investigated. The results, which will be discussed in further detail, indicate that adjusting these parameters allows for control over the length, thickness, density, and morphology of the nanowires.


2009 ◽  
Vol 48 (19) ◽  
pp. 3469-3472 ◽  
Author(s):  
Lixuan Mu ◽  
Wensheng Shi ◽  
Guangwei She ◽  
Jack C. Chang ◽  
Shuit-Tong Lee

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.


2016 ◽  
Vol E99.C (2) ◽  
pp. 285-292 ◽  
Author(s):  
Tran THI THU HUONG ◽  
Hiroshi SHIMADA ◽  
Yoshinao MIZUGAKI

Author(s):  
Jiko Raut ◽  
Prithidipa Sahoo

Abstract:: Thiol-containing amino acids and peptides play crucial roles in many physiological processses. For example, Cysteine (Cys) and Homocysteine (Hcy) are considered to be related to a number of health disorders such as renal failure, AIDS, Alzheimer’s and Parkinson’s diseases, atherosclerotic cardiovascular diseases, neutral tube defects, and coronary heart disease. Glutathione (GSH), an important tripeptide with a thiol group, performs vital biological functions that are in-volved in combating oxidative stress and maintaining redox homeostasis. Cysteine also plays important roles in our bodies as an antioxidant, a metal cofactor binder in enzymes, and a protein structure stabilizer by disulfide bond formation in the proteins. Hcy are involved in cellular growth and GSH in redox homeostasis. Hence, the rapid, sensitive, and selective de-tection of such biothiols is of considerable importance and significant interest. Different fluorescent chemosensors have been introduced to develop and improve the detection techniques and accuracy of these biothiols. In this review article we have presented some research works to show a guiding principle for the design of effective chemosensors which are highly sensitive and selective for the detection of particular a group of biothiols in aqueous medium. In line with these develop-ments, the researchers have developed novel chemosensors that signal binding events of these above mentioned biothiols through their optical properties. The binding mechanism and properties have also been established with different theoretical studies. Their applications in the form of colorimetric kit, logic gates, live cell imaging, and quantification from different bi-ological samples have also been developed.


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