UV-Vis Wavelength Range Research Articles

Processing natural bamboo into white bamboo through photocatalyzed lignin oxidation

Scalable and highly efficient bamboo whitening remains a great challenge. Herein, an effective bamboo whitening strategy is proposed based on photocatalyzed oxidation, which involves H2O2 infiltration and UV illumination. The as-prepared white bamboo well maintains the nature structure of natural bamboo and demonstrates high whiteness and superior mechanical properties. The absorbance value is significantly decreased to 3.5 and the transmittance is increased to 0.04 % in UV–visible wavelength range due to the removal of light-absorbing chromospheres of lignin, resulting in a high whiteness when the UV illumination time is 8 h. In addition, the white bamboo displays a high tensile strength of 30 MPa and a high flexural strength of 36 MPa due to the well-preserved lignin units (lignin preservation is about 89 %). XRD patterns and analysis show that photocatalyzed oxidation has no effect on the crystal parameters of cellulose. Compared with the traditional bamboo whitening technology, our photocatalyzed oxidation strategy demonstrates significant advantage including chemical and time conservation, high efficiency, environment friendliness, and mechanical robustness. This highly efficient and environmentally friendly photocatalyzed oxidation strategy for the fabrication of white bamboo may pave the way of bamboo-based energy-efficient structural materials for engineering application.

Constructing diverse switchable circularly polarized luminescence via a single azobenzene polymer film

Recently circularly polarized luminescence (CPL) materials have attracted significant interest. Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields, such as in high-level information encryption. Here, we provided a novel and general strategy involving handedness-selective filtration and ground-state chiral self-recovery (CSR) in double film system to address this issue. Based on this strategy, we achieved CPL switch through the reversible modulation of ground-state chirality including absorption and scattering circular dichroism (CD) signals over the full UV-visible wavelength range (365-700 nm) in a single azobenzene polymer (PAzo) film. More importantly, by flexibly changing the type of fluorescent films, it is convenient to achieve general excited-state CSR, that is reversible switching of full-color including ideal white (CIE coordinate (0.33, 0.33)), as well as room-temperature phosphorescent CPL. All these CPL signals without almost any intensity decay after three cycles of on-and-off switching. Experimental results indicated that the trans-cis isomerization and ordered rearrangement of azobenzene units in PAzo film were the fundamental reasons for realizing CPL switching. Finally, based on this system we achieved dynamic visual encryption and decryption process including multiple decryption methods. This study provides an effective method for constructing a universally applicable chiroptical switch in excited state.

Effect of Al Concentration on Structural, Optical and Electrical Properties of (Gd, Al) Co-Doped ZnO and Its n-ZnO/p-Si (1 0 0) Heterojunction Structures Prepared via Co-Sputtering Method

Heterojunction structures of n-ZnO/p-Si were prepared through the growth of undoped ZnO and (Gd, Al) co-doped ZnO films onto p-type Si (1 0 0) substrates, using a co-sputtering method. The structural and optical properties of the Gd-doped ZnO films were studied as a function of different Al doping concentrations. The X-ray diffraction profiles indicated that the films had a nanocrystalline structure of ZnO with a (0 0 2) preferential orientation. An increase in the Al doping concentration deteriorated the (0 0 2) diffraction peak intensity. The transmittance measurements in the UV-Vis wavelength range indicated that the film's optical gap increased with increase in Al doping concentration. The heterojunction parameters were evaluated using the current-voltage (I-V) characterization carried out of the fabricated n-ZnO/p-Si heterostructure, in dark conditions at room temperature. From these measurements, the n-ZnO-based DMS/p-Si heterojunction diode with the use of (Gd, Al) co-doped ZnO film showed the lowest leakage current of 1.28 × 10-8 A and an ideality factor η of 1.11, close to the ideal diode behavior of η = 1, compared to the n-Gd-doped ZnO/p-Si and n-undoped ZnO/p-Si heterojunction diodes.

THE EFFECT OF 0.1 WT% IODINE ADDITION ON THE OPTICAL PROPERTIES OF POLYETHYLENE OXIDE FILMS

The study aimed to investigate the optical properties of thin films made of polyethylene oxide dispersed with dopants of a fixed amount of iodine (0.1 wt %). The films prepared by the casting method were optically investigated as a function of the iodine fillers. The study used a UV-visible spectrophotometer technique with a wavelength ranging from (200 to 800) nm and determined the absorption coefficient, refractive index, energy gap, extinction coefficient, optical conductivity, and dielectric constant in the UV-visible wavelength range. The results showed a noticeable change in these optical values with polyethylene oxide doped with 0.1 wt% iodine composites compared with the pure polyethylene oxide films. These measured values of polyethylene oxide doped with 0.1 wt% iodine depend on the wavelength of the incident ultraviolet light.

Role of dielectric medium on optical behaviour of blue emitting colloidal MoS2 quantum Dots

In this work, we report colloidal synthesis of blue emitting MoS2 quantum dots (QDs). The emission characteristics, being dependent on the surface defect states, can be tuned by engineering the QD – dielectric interface. We have reported an investigation of interaction between dispersing medium and MoS2 QDs. The MoS2 QDs have shown different optical behaviour in three different dispersing dielectric media: non-polar (hexane), electron acceptor (chloroform) and an electron donor (dimethylformamide). As synthesized MoS2 QDs absorb in the UV and emit in the UV–Vis wavelength range from 2 to 4 eV with emission maxima at ∼3 eV. A significant decrease to ∼62 nm in the FWHM value of emission spectra has been obtained for QDs dispersed in DMF along with no shift in the maxima at various excitation wavelengths due to quenched surface dangling states and sulfur (S2−) vacancies leading to decreased non-radiative decay pathways. Our synthesized MoS2 QDs have shown the excitation dependent photoluminescence behaviour with a redshift in the emission peak with increasing excitation wavelength. This redshift can be attributed to the polydisperse nature of the MoS2 QDs as well as the presence of surface defect states.

Solvent effects on chemical composition and optical properties of extracted secondary brown carbon constituents

Brown carbon (BrC) aerosol is an important contributor to positive radiative forcing on Earth, but its influence on the global radiative budget remains uncertain due to the limitations of current analytical methods used to characterize its optical and chemical properties. While online optical instruments provide in situ characterization of BrC light-absorption properties, the wavelengths are often limited due to the light source of optical instruments. Offline measurements can cover the entire UV–Vis wavelength range, but the use of solvents may introduce artifacts. In this study, we compared the mass absorption coefficients at 375 nm (MAC375) measured by online and offline instruments for aerosol samples generated from the nighttime oxidation of heterocyclic volatile organic precursors. Offline samples were extracted with both acetonitrile (ACN) and methanol (MeOH) to investigate the potential solvent effects on the Ångström absorption exponent and BrC chromophores. Our results indicated considerable variations between MeOH-extracted samples and ACN-extracted samples, with pyrrole SOA being especially susceptible to solvent effects. Multi-instrumental analysis confirmed that MeOH could induce solvent artifacts by reacting with conjugated carbonyl chromophores, such as phthalic anhydride, maleic anhydride and maleimide, and subsequently modify the light absorption properties of BrC constituents. Our findings highlight the importance of methanolysis in the formation of artifacts, whereas an inert solvent such as ACN would be ideal for proper characterization of BrC chromophores. Consequently, the results from offline analysis using MeOH as the solvent should be interpreted with caution.Copyright © 2022 American Association for Aerosol Research

Linking the chemical composition and optical properties of biomass burning aerosols in Amazonia

The absorption efficiency of chemically resolved organic aerosols of Southwestern Amazonia showed strong spectral dependence and significant light absorption in the UV-vis wavelength range indicating the presence of organic species that act as BrC.

Scattering and absorption cross sections of atmospheric gases in the ultraviolet–visible wavelength range (307–725 nm)

Abstract. Accurate Rayleigh scattering and absorption cross sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross sections are also essential for calibrating high-finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using broadband cavity-enhanced spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of (0.4 ± 1.2) %, (−0.6 ± 1.1) %, (0.9 ± 1.4) %, (2.8 ± 1.2) %, and (0.9 ± 2.2) %, respectively. The O2–O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV–vis wavelength range. This study provides dispersion relations for refractive indices, n-based Rayleigh scattering cross sections, and absorption cross sections based on more continuous and more extended wavelength ranges than available in the current literature.

UV–Vis–NIR broadband response of GaAs-based photocathode with multilayer graded-band cascade structure

To improve the lattice matching, quantum efficiency and response range of the transmission-mode GaAs-based photocathode , a novel photocathode with multilayer graded-band cascade emission layer is proposed. The one-dimensional steady-state continuity equations and finite-difference time-domain methods are utilized to obtain the quantum efficiency and optical absorption characteristics of the proposed photocathode, respectively. The results show that, the built-in electric fields generated by the varying-composition and varying-doping structure can assist the photoelectrons generated in the sublayer itself and the front sublayers to transport towards the emitting surface and escape to the vacuum. Compared with the conventional AlGaAs/InGaAs structure, the proposed structure possesses better lattice matching and enhanced quantum efficiency in the UV and NIR wavelength range. A three-fold increase of quantum efficiency can be realized at 400 nm and the theoretical quantum efficiency at 1064 nm can reach 2%. Besides, the integral absorptivity is increased by 6.8% in the visible wavelength range, and 12.9% in the NIR wavelength range. It is found that the increase of the thickness of AlGaAs sublayer and GaAs sublayer mainly reduces the quantum efficiency in the UV–Vis wavelength range. When the InGaAs sublayer is thin enough, the increase of thickness would enhance the quantum efficiency in the NIR wavelength range and deteriorate that in the UV–Vis wavelength range. This work can contribute to the performance improvement of UV–Vis–NIR broadband GaAs-based photocathode. • A transmission-mode photocathode with multilayer graded-band cascade structure is proposed. • The quantum efficiency model of the proposed multilayer structure is deduced. • The quantum efficiency and optical absorption characteristics are investigated. • The lattice matching, quantum efficiency and response range are improved.

Studied Report: Two Dimension Electric Field Simulation Effect of Zinc Oxide Nanorod Arrays for Glucose-Blood Monitoring

Diabetes is one of the most common diseases globally that is caused by glucose. Glucose binds to hemoglobin in Red Blood Cell in minor unit Haemoglobin A1c (HbA1c). A large HbA1c concentration in blood indicates that a person has diabetes. This study has the aim to determine the different electric field distribution along with the different concentrations of glucose on blood. Nanorod arrays in this research produced from previous research with AAO template, then ZnO deposited inside with geometry size 150x150x500 nm are irradiated with light in the UV Vis wavelength range. The medium in this research was on a blood model with different glucose concentrations which have low glucose (hypoglycemia), normal glucose blood, and high glucose concentration (hyperglycemia). Electric field distribution depends on medium and wavelength analysed to determine the optimal value for Glucose-Blood monitoring. The result shows that the distribution pattern of the electric field at ZnO nanorod arrays with different mediums has a different value. It indicated from electric field maximum peak, the color contour of electric field distribution, and the absorbance of ZnO nanorod arrays. Finally, we got the optimal wavelength use for glucose blood monitoring was on wavelength around 400 nm.

Optical constants of Pluto aerosol analogues from UV to near-IR

Photochemical aerosols were detected as high as 350 km of altitude in Pluto's atmosphere during the New Horizons fly-by. These aerosols are thought to affect Pluto's climate, by acting as cooling agents, and the colours of Pluto's surface, in particular in the dark regions named Cthulhu and Krun and at the North Pole. Pluto atmospheric and surface models have so far used the optical constants of Titan aerosol analogues (tholins), whereas their chemical composition is known to differ from that of Pluto aerosol analogues.In order to provide a new set of optical constants for Pluto tholins, we synthesized analogues of Pluto's aerosols and determined with spectroscopic ellipsometry their optical constants from 270 to 2100 nm. Three types of samples were produced from N2:CH4:CO gas mixtures differing in their CH4:N2 mixing ratio, representative of different altitudes in Pluto's current atmosphere or different seasons or epochs of Pluto.Our analysis shows a strong absorption by Pluto tholins in the UV and visible spectral ranges, with k index of a few 10−1 at 270 nm, in agreement with N- and O-bearing organic molecules. Pluto tholins are less absorbent in the near-IR than in the UV–Vis wavelength range, with k of a few 10−3 between 600 and 2100 nm. Our comparative study highlights the dependency of n and k indices to the CH4:N2 mixing ratio. Aerosols formed at different altitudes in Pluto's atmosphere or during different seasons or epochs of Pluto will therefore affect the budget of Pluto radiative transfer differently.The optical constants presented in this study were tested with a Pluto surface model and with a model of light scattering. The surface modelling results highlight the suitability of these optical constants to reproduce Pluto compositional observations in the visible spectral range by MVIC and LEISA. The atmospheric modelling results conclude that Pluto tholins absorb 5 to 10 times less than Titan tholins at 500 nm, and this lower absorption is consistent with Alice observations of Pluto's haze.

Investigation of structural, morphological, optical and electrical properties of Co/Ni co-doped ZnO thin films

This work reports on the preparation and characterization of zinc oxide (ZnO) thin films using spray pyrolysis technique on glass substrates. The effect of cobalt and nickel doping and nickel/cobalt co-doping on the structural, optical, morphological and electrical properties of obtained films have been investigated. The obtained films are characterized by different techniques such as X-rays diffraction (XRD), UV-Visible, Scanning electron microscopy (SEM) and four probes electrical measurements. The results of the XRD characterization indicate that all the films of interest have the wurtzite hexagonal polycrystalline structure with (002) preferred orientation. Images of scanning electron microscopy (SEM) were used to observe the effect of doping and co-doping on films surface. Spectroscopy measurements in UV-VIS wavelength range have found to give good values of transmission (average value = 85%) for all elaborated layers, with a high transmission of 93% for the film deposited at 3%Ni. The films exhibit high transmittance around 85% with the presence of interference fringes in the visible region, indicating the films homogeneity and smoothness. The deduced optical gap values from optical measurement are found to be in the range of 3.26–3.30 eV. The electrical analysis shows that the conductivity increases with the co-doping compared to the pure ZnO film. The characterization of ZnO film co-doped 3%Ni:3%Co showed that the material under focus is a good candidate for optoelectronic applications such as the manufacture of solar cells with transparent electrodes.

Investigation of negative magneto-conductance properties of cobalt phthalocyanine thin films

The opto-electrical and magnetic field effects on cobalt phthalocyanine (CoPc) thin film single layer device were explored. The root mean square roughness of thin film was 5.8 nm. The mobility was estimated for space charge limited current region in the current–voltage characteristics. Magnetic field effect on injection current was studied in terms of organic magneto-conductance. The negative magneto-conductance (MC) was observed in CoPc thin film diode at different bias voltages. The negative values of MC were found to be 10.05, 8.29, 6.84, 4.98 and 3.13% for applied bias voltages 1, 2, 3, 4 and 5 V, respectively. The CoPc thin film absorbed the UV–visible wavelength range which were represented by two bands of CoPc molecule, B band and Q band. MC study of device under dark and light reveals the formation of trap assisted bipolarons and their quenching by the formation of photogenerated excitons. The device was checked for the resistive and capacitive behaviour by impedance spectroscopy. The contact resistance is approximately constant ~ 66 Ω at all applied bias voltages. The bulk and interface resistance vary from 1.8 to 0.6 kΩ and 50.06 to 1.43 kΩ, respectively. Similarly, the bulk and interface capacitance vary from 55.81 to 10.56 nF and 50.47 to 558.09 nF, respectively for applied bias voltages.

Band-correlated barrier-hopping conduction in α-NiMoO4 micro-crystals and comparison of its energy storage performance with MWCNT-integrated complex

Monoclinic nickel molybdate (NiMoO4) micro-crystals were synthesized via a conventional solid-state synthesis route with a prospective to investigate its conductivity response with high-temperature evolution and phenomenal electrochemical performance for supercapacitor application. The tenacious phase formation, Raman active phonon vibration and metal oxide (Ni–O, Mo–O) stretching vibration in octahedral and tetrahedral sites of as-synthesized NiMoO4 were confirmed by X-ray diffraction techniques, Raman and FTIR spectra. The UV-DRS absorbance spectra of NiMoO4 exhibits several effective absorption peaks in the UV–Visible wavelength range (200–800 nm). The optical band gap of NiMoO4 was estimated at 2.50 eV experimentally with the famous Kubelka–Munk equation and theoretically correlated with the result obtained from the density of states (DOS) calculation. The saturation magnetization of NiMoO4 diminished from 0.0026 to 0.0013 emu g−1. significantly due to the embodiment of MWCNT but the coercivity maintain a minute change. Lessening of real (Z′) and imaginary impedance (Z″) with temperature was observed with high-temperature evolution (633–773 K) and the Nyquist plots were well fitted with equivalent circuit model (QR)(QR)(CR) network. The temperature-dependent frequency exponent (n) suggested the band-correlated barrier-hopping process in high temperature for the conduction mechanism of NiMoO4. The maximum specific capacitance (Csp) was estimated 518 F g−1 for NiMoO4 at current density 5 Ag−1 and its value intensified up to 1050 A g−1 at current density 5 Ag−1 in MWCNT-integrated NiMoO4. Imperatively, the upmost energy density 66.12 Wh Kg−1 was detected at power density 1075 W Kg−1 for MWCNT-blended NiMoO4 which is significantly larger than pristine NiMoO4 (energy density 42.28 Wh Kg−1 at power density 612 W Kg−1) at a current density 5 Ag−1, which reveals their great potential application as a supercapacitor and energy storage technology.

The impact of the carrier gas composition of non-thermal atmospheric pressure plasma jet for bacteria sterilization

In this work, the bacteria inactivation using the nonthermal atmospheric pressure plasma has been studied. The bacteria inactivation was conducted using a self-design nonthermal atmospheric pressure plasma jet system. During this experiment, Escherichia coli was used as an objective microorganism. The primary operating gas for the plasma jet used in this work is helium, and small fractions of oxygen or nitrogen (0.2%) were used as the secondary gas. The three plasma jet cases were operated at 3.5 kV, 14 l/m, and 7 mm, which represented the applied voltage, gas flow rate, and distance from the nozzle, respectively. The types of reactive species have been examined using optical emission spectroscopy. The gas temperature and optical emission spectrum were measured under the same condition. The active species of OH, OII, OI, N21+, N22+, and He are indented in the UV-vis wavelength range. The inactivation of E. coli bacteria has occurred after 20 s of nonthermal plasma treatment, whether the carrier gas is pure helium or helium + nitrogen or helium + oxygen. The results revealed that the impact of helium is less than that of helium + 0.2% nitrogen which is less than that of helium + 0.2% oxygen. The current results of this experiment could be utilized in improving the nonthermal plasma jet for extended surface decontamination.

Phase-pure iron pyrite (FeS2) micro- and nano-sized crystals synthesized by simple one-step microwave-assisted hydrothermal method

Iron pyrite micro- and nano-sized crystals are desirable as active materials in lithium ion batteries and photovoltaics, and are particularly suitable for nanocrystal inks for roll-to-roll deposited or ink-jet printed solar cells. In this paper we report the synthesis of iron pyrite micro- and nano-sized crystals via simple and convenient green one-step microwave-assisted hydrothermal (M − H) process at relatively low growth temperatures, using commonly used precursors such as FeCl3, Na2S and S8 and. The structural, morphological and optical properties of the resulting nanostructured materials have been thoroughly investigated for two typical M − H growth temperatures. X-ray diffraction (XRD) pattern and Raman data revealed good crystalline quality for the as synthesized pyrite NCs. Typical XRD patterns show the dominant peaks which can be indexed as a pure cubic phase of FeS2, with lattice constant values close to the lattice parameters reported for FeS2, and in agreement with a stoichiometric pyrite phase. XRD and Raman analysis also confirm that no other impurities phases such as hexagonal FeS, marcasite, pyrrhotite, greigite, S or Fe–O compounds were detected, confirming the high purity of the synthesized iron pyrite nanocrystals. Various shapes of pyrite like quasi-cubic, cubic and flower-like FeS2 nanocrystals have been observed, which can be modulated by using different synthetic conditions. The sizes of the pyrite micro- and nanostructures were in the range of 150 nm to 1 μm as obtained. The present study indicates that the M − H method is a facile one-step way to obtain phase pure iron pyrite micro- and nano-sized crystals. Optical characterization confirms direct bandgap transitions (values of 2.61 eV and 2.55 eV for iron pyrite NCs samples hydrothermal grown at 130 °C and 160 °C, respectively), and indirect bandgap transitions (values of 1.19 eV and 1.52 eV for samples hydrothermal grown at 130 °C and 160 °C, respectively). Optical studies show high absorbance in the entire UV–Vis wavelength range making the as-synthesized pyrite nanocrystals potential candidate as absorber in nanoscale photovoltaic solar cells.

Development of Label-Free Colorimetric Assay for MERS-CoV Using Gold Nanoparticles.

Worldwide outbreaks of infectious diseases necessitate the development of rapid and accurate diagnostic methods. Colorimetric assays are a representative tool to simply identify the target molecules in specimens through color changes of an indicator (e.g., nanosized metallic particle, and dye molecules). The detection method is used to confirm the presence of biomarkers visually and measure absorbance of the colored compounds at a specific wavelength. In this study, we propose a colorimetric assay based on an extended form of double-stranded DNA (dsDNA) self-assembly shielded gold nanoparticles (AuNPs) under positive electrolyte (e.g., 0.1 M MgCl2) for detection of Middle East respiratory syndrome coronavirus (MERS-CoV). This platform is able to verify the existence of viral molecules through a localized surface plasmon resonance (LSPR) shift and color changes of AuNPs in the UV–vis wavelength range. We designed a pair of thiol-modified probes at either the 5′ end or 3′ end to organize complementary base pairs with upstream of the E protein gene (upE) and open reading frames (ORF) 1a on MERS-CoV. The dsDNA of the target and probes forms a disulfide-induced long self-assembled complex, which protects AuNPs from salt-induced aggregation and transition of optical properties. This colorimetric assay could discriminate down to 1 pmol/μL of 30 bp MERS-CoV and further be adapted for convenient on-site detection of other infectious diseases, especially in resource-limited settings.

Plasmonic Metasurfaces with High UV–Vis Transmittance for Photopatterning of Designer Molecular Orientations

AbstractRecent developments of utilizing plasmonic metasurfaces in photopatterning of designer molecular orientations have facilitated numerous new applications of liquid crystals; while the optical efficiency of the metamasks remains a critical issue, especially in the UV region. Here a new design of plasmonic metasurfaces made of parallelepiped arrays is presented which yield very high and broadband transmission in the UV–vis wavelength range. It is shown that this plasmonic metamask exhibits two polarization peaks originated from a cavity mode and lattice resonance respectively and demonstrated that complex designer molecular orientations can be photopatterned by using this metamask with significantly reduced exposure time. This type of high‐efficiency broadband plasmonic metasurfaces is not only important for high resolution photopatterning of molecular orientation but also tailorable for various other flat optics applications in the UV and near UV regions.

AlGaN optimization for photodetectors

AlGaN/GaN-based photodetectors are of great interest for applications involving detection and imaging in the UV–visible wavelength range. In this work we present the results of phototransistors parameters simulation based on Sim Windows for improving efficiency and performance characteristics. We carried the out optimization in active area and an additional doping level profile. The Al mole fraction in the collector and emitter was varied from X = 0.2 to X = 0.3 during simulation. AlGaN-based HPT with an aluminum concentration 28% provides promising performance maximum efficiency with the highest sensitivity.

Excitation of plasmonic resonances within UV-Vis wavelength range using low-purity aluminum nanoconcave arrays

Size-controllable aluminum nanoconcave arrays were synthesized by electrochemical anodization of high and low-purity aluminum foils using oxalic, phosphoric, and citric acids. The plasmonic properties of the nanoconcave arrays in the two types of Al were investigated based on the specular reflectance in the 190–1400 nm wavelength range. We found that their optical reflectance was dramatically reduced as compared with unstructured Al. At the same time, pronounced reflectivity dips were detectable in the 280–1250 nm wavelength range for the case of high-purity aluminum, while for low-purity aluminum, they were within 260–580 nm, which were ascribed to plasmonic resonances of first and second orders. As a proof of principle of an application, we placed graphene on top of the nanoconcave arrays and observed a Surface Enhanced Raman Scattering (SERS) effect that resulted in an intensity increase in the characteristic G and 2D bands of graphene induced by the plasmonic properties of Al nanoconcave arrays. The maximum increase was achieved when the plasmonic resonance almost matched with the wavelength of the excitation laser probe of the Raman system. This study is important since we used low purity aluminum at a low cost to design and fabricate SERS substrates which can be used in practical applications.