scholarly journals Fabrication and study of Raman signal enhancement of pyramid/nano-Ag structured Silic substrate

2021 ◽  
Vol 4 (1) ◽  
pp. 21-23
Author(s):  
Nguyet Dau Tran Anh ◽  
Hieu Van Vo Kim ◽  
Thanh Van Tran Thi ◽  
Luan Huynh Nguyen Thanh ◽  
◽  
...  
Keyword(s):  
Silicon Substrate ◽  
Enhancement Factor ◽  
Isopropyl Alcohol ◽  
Rhodamine 6G ◽  
Alcohol Concentration ◽  
Raman Signal ◽  
Enhancement Effect ◽  
Optimal Parameters ◽  
Chemical Corrosion ◽  
20 Nm

The pyramid-structured silicon substrate was successfully fabricated by a chemical corrosion method with an average thickness of about 1 - 3 μm with the optimal parameters such as corrosion temperature of 70oC, corrosion time of 5 min, concentration KOH of 3 M and isopropyl alcohol concentration of 1 M. After that, the silver nanoparticles layer (thickness 20 nm) was coated on the silicon substrate by a sputtering method to enhance the SERS signal. The results proved that the Pyramid/nano Ag structure silicon substrate showed the enhancement effect of Raman signal, and Rhodamine 6G pigment in food at low concentration (10-6 M) was detected and the enhancement factor was 9.7 × 102.

scholarly journals Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Md. Wahadoszamen ◽  
Arifur Rahaman ◽  
Nabil Md. Rakinul Hoque ◽  
Aminul I Talukder ◽  
Kazi Monowar Abedin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Rhodamine 6G ◽  
Detection Efficiency ◽  
Colloidal Suspension ◽  
Surface Enhanced Raman Spectroscopy ◽  
Laser Raman Spectroscopy ◽  
Raman Signal ◽  
Fluorescence Signal ◽  
Present System

A dispersive Raman spectrometer was used with three different excitation sources (Argon-ion, He-Ne, and Diode lasers operating at 514.5 nm, 633 nm, and 782 nm, resp.). The system was employed to a variety of Raman active compounds. Many of the compounds exhibit very strong fluorescence while being excited with a laser emitting at UV-VIS region, hereby imposing severe limitation to the detection efficiency of the particular Raman system. The Raman system with variable excitation laser sources provided us with a desired flexibility toward the suppression of unwanted fluorescence signal. With this Raman system, we could detect and specify the different vibrational modes of various hazardous organic compounds and some typical dyes (both fluorescent and nonfluorescent). We then compared those results with the ones reported in literature and found the deviation within the range of ±2 cm−1, which indicates reasonable accuracy and usability of the Raman system. Then, the surface enhancement technique of Raman spectrum was employed to the present system. To this end, we used chemically prepared colloidal suspension of silver nanoparticles as substrate and Rhodamine 6G as probe. We could observe significant enhancement of Raman signal from Rhodamine 6G using the colloidal solution of silver nanoparticles the average magnitude of which is estimated to be 103.

scholarly journals Stacked Dual-Band Quantum Well Infrared Photodetector Based on Double-Layer Gold Disk Enhanced Local Light Field

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2695
Author(s):  
Chang Liu ◽  
Xuan Zuo ◽  
Shaohui Xu ◽  
Lianwei Wang ◽  
Dayuan Xiong
Keyword(s):  
Active Region ◽  
Quantum Well ◽  
Quantum Wells ◽  
Double Layer ◽  
Enhancement Factor ◽  
Coupling Efficiency ◽  
Dual Band ◽  
Enhancement Effect ◽  
Infrared Photodetector ◽  
Quantum Well Infrared Photodetector

We propose a stacked dual-band quantum well infrared photodetector (QWIP) integrated with a double-layer gold disk. Two 10-period quantum wells (QW) operating at different wavelengths are stacked together, and gold nano-disks are integrated on their respective surfaces. Numerical calculations by finite difference time domain (FDTD) showed that the best enhancement can be achieved at 13.2 and 11.0 µm. By integrating two metal disks, two plasmon microcavity structures can be formed with the substrate to excite localized surface plasmons (LSP) so that the vertically incident infrared light can be converted into electric field components perpendicular to the growth direction of the quantum well (EZ). The EZ electric field component can be enhanced up to 20 times compared to the incident light, and it is four times that of the traditional two-dimensional hole array (2DHA) grating. We calculated the enhancement factor and coupling efficiency of the device in the active region of the quantum well. The enhancement factor of the active region of the quantum well on the top layer remains above 25 at the wavelength of 13.2 μm, and the enhancement factor can reach a maximum of 45. Under this condition, the coupling efficiency of the device reaches 2800%. At the wavelength of 11.0 μm, the enhancement factor of the active region of the quantum well at the bottom is maintained above 6, and the maximum can reach about 16, and the coupling efficiency of the device reaches 800%. We also optimized the structural parameters and explored the influence of structural changes on the coupling efficiency. When the radius (r1, r2) of the two metal disks increases, the maximum coupling efficiency will be red-shifted as the wavelength increases. The double-layer gold disk structure we designed greatly enhances the infrared coupling of the two quantum well layers working at different wavelengths in the dual-band quantum well infrared photodetector. The structure we designed can be used in stacked dual-band quantum well infrared photodetectors, and the active regions of quantum wells working at two wavelengths can enhance the photoelectric coupling, and the enhancement effect is significant. Compared with the traditional optical coupling structure, the structure we proposed is simpler in process and has a more significant enhancement effect, which can meet the requirements of working in complex environments such as firefighting, night vision, and medical treatment.

Metastability of tetragonal ZrO2 derived from Zr-n-propoxide-acetylacetone-water-isopropyl alcohol

1998 ◽  
Vol 13 (8) ◽  
pp. 2174-2183 ◽  
Author(s):  
Zhaoqi Zhan ◽  
Hua C. Zeng
Keyword(s):  
Transformation Temperature ◽  
Isopropyl Alcohol ◽  
Tetragonal Zro2 ◽  
Surface Oxygen ◽  
Crystallite Growth ◽  
Calcination Temperatures ◽  
Work Surface ◽  
20 Nm ◽  
Temperature Time ◽  
Thermodynamic Factors

ZrO2 nanopowders derived from zirconium n-propoxide [Zr(OC3H7)4]-acetylacetone-water-isopropanol have been investigated with respect to their tetragonal metastability on heating-cooling processes. The transformation temperature of metastable tetragonal to monoclinic (t′ → m) phase is found to be governed by ultimate firing temperature, time, and atmospheres employed. Crystallite growth is fastened with increase in calcination temperatures over 1000–1400 °C, and the t′ → m transformation temperature is correlated linearly with crystallite size in the studied range of 12–20 nm. Heating in an oxygen environment increases the size of the final crystallites and hence the rate of the t′ → m transformation. It is revealed that the t′ → m transformation temperature depends largely on the heating atmosphere, but only weakly on the cooling one. Based on the findings of this work, surface oxygen deficiencies are attributed to be responsible for low-temperature tetragonal metastability. A crystallite growth model to explain the decline of t′-ZrO2phase is proposed. Kinetic and thermodynamic factors are also discussed in connection with the existing theories of tetragonal metastability.

scholarly journals The surface-enhanced resonance Raman scattering of dye molecules adsorbed on two-dimensional titanium carbide Ti3C2Tx (MXene) film

2020 ◽  
Vol 1 (2) ◽  
pp. 146-152 ◽  
Author(s):  
Satheeshkumar Elumalai ◽  
John R. Lombardi ◽  
Masahiro Yoshimura
Keyword(s):  
Raman Scattering ◽  
Titanium Carbide ◽  
Crystal Violet ◽  
Enhancement Factor ◽  
Resonance Raman ◽  
Raman Signal ◽  
Two Dimensional ◽  
Dye Molecules ◽  
Resonance Raman Scattering ◽  
Surface Enhanced

The resonance Raman signal enhancement of crystal violet dyes onto the two-dimensional MXene–Ti3C2Tx film, so called MXenes-enhanced resonance Raman scattering (MERRS), is reported with a calculated enhancement factor of 3.42 × 109.

The Raman enhancement effect on a thin GaSe flake and its thickness dependence

2015 ◽  
Vol 3 (42) ◽  
pp. 11129-11134 ◽  
Author(s):  
Lin Quan ◽  
Yuqing Song ◽  
Yue Lin ◽  
Guanghui Zhang ◽  
Yanmeng Dai ◽  
...  
Keyword(s):  
Thickness Dependence ◽  
Raman Signal ◽  
Enhancement Effect ◽  
Raman Enhancement

The GaSe flake can enhance Raman signal and the effect decreases with its thickness.

Fabrication of Silver Nanoparticle Decorated AFM Tips for Tip-Enhanced Raman Scattering Applications

2013 ◽  
Vol 643 ◽  
pp. 195-198 ◽  
Author(s):  
Yu Hua Li ◽  
Chang Hui Xu ◽  
Min Han
Keyword(s):  
Gas Phase ◽  
Silver Nanoparticle ◽  
Enhancement Factor ◽  
High Yield ◽  
Raman Signal ◽  
Simple Method ◽  
Atomic Force ◽  
Afm Tips ◽  
Enhanced Raman Scattering ◽  
Tip Enhanced Raman Spectroscopy

We report on a simple method for the fabrication of metalized tips by depositing gas-phase synthesized silver nanoparticles onto atomic force microscope (AFM) tips. The method enables fabricating tips suitable for AFM based tip-enhanced Raman spectroscopy (TERS) with high yield. The performance of the fabricated silver nanoparticle decorated tips is examined by detecting low concentration BPE molecules using a transmission mode TERS setup. An 30-fold enhancement of the Raman signal is shown. The net TERS enhancement factor is calculated to be about 1000.

scholarly journals 2D-ARRRAYS OF CU NANODISKS ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATE FOR SERS APPLICATIONS

2019 ◽  
Vol 34 (4) ◽  
Author(s):  
Thi Yen Mai Nguyen
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Rhodamine 6G ◽  
Resonance Absorption ◽  
Enhancement Effect ◽  
Aao Template ◽  
Anodic Aluminum ◽  
Oxide Substrates ◽  
2D Arrays ◽  
Lift Off

Copper nanodisks (Cu NDs) of 50 nm were prepared on square-inch anodic aluminum oxide substrates by sputtering method. The samples were annealed at 450oC, then the walls of AAO substrates were lift off in a solution of acid phosphoric. The 2D arrays of Cu NDs were fabricated in high quality. Morphology of the substrates were observed by scanning electron microscopy. Surface plasmon resonance absorption was observed with different peaks in the range of 400-1400nm wavelengths that means the substrate is promising for SERS application. To demonstrate, we observed Raman spectrum of Rhodamine 6G using the enhancement effect of the substrate.  

scholarly journals One Step Fabrication of Highly Absorptive and Surface Enhanced Raman Scattering (SERS) Silver Nano-trees on Silicon Substrate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sara Abdel Razek ◽  
Ahmed B. Ayoub ◽  
Mohamed A. Swillam
Keyword(s):  
Raman Scattering ◽  
Ethylene Glycol ◽  
Silicon Substrate ◽  
Enhancement Factor ◽  
High Sensitivity ◽  
Surface Enhanced Raman Scattering ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
One Step ◽  
Enhanced Raman Scattering

Abstract Silver Nano-trees (AgNTs) were synthesized by one-step electroless method with different densities via water or ethylene glycol (EG) on silicon substrate in one minute. The density of AgNTs is controlled by changing the concentration of silver nitrate in etchant solution. The absorption of NTs fabricated via EG is higher than absorption of NTs without EG. The AgNTs are employed as substrates for surface-enhanced Raman scattering (SERS) and exhibit high sensitivity. The silver Nano-trees fabricated via ethylene glycol (AgNTs-EG) enhances the Raman spectrum of pyridine (Py) with higher enhancement factor. Moreover, the SERS-active substrates prepared by using EG were able to detect Pyridine with concentration as low as 0.005 mM, the ones fabricated by water could only detect Pyridine at concentration of 0.2 mM.

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