Efficiency of Silver Nanoparticles in third Generation Solar Cells

Immense energy is required for the production of first generation solar cells and they also tend to be rigid. There are lower efficiencies of the second generation solar cells than the first generation solar cells. On the other hand, the durability and efficiency of the third generation solar cells is more than the first generation solart cells. Moreover, the third generation solar cells are not available commercially and this area of solar cells requires more research and development. The current research works makes use of silver nanoparticles to enhance the efficiency of third generation solar cells. Silver nanoparticles were first made and then the solar cells were fabricated. Titanium and platinum electrodes were used. The titanium electrode was immersed in the silver nanocluster solution for 12 hours after which the electrodes were then clipped together. Solar simulator was used in the research work for testing the efficiency of the solar cells. The efficiency was calculated to be 3.46%. The results of the research work suggest that silver nanoparticles can essentially enhance the efficiency of third generation solar cells

Pressure Sensitive Sensors Based on Carbon Nanotubes, Graphene, and Its Composites

Carbon nanotubes (CNTs) and graphene have attracted a great deal of interest due to their outstanding mechanical, optical, electrical, and structural properties. Most of the scientists and researchers have investigated the optical and electrical properties of these materials. However, due to unique electromechanical properties of these materials, it is required to explore the piezoresistive properties of bulk nanostructured CNTs, graphene, and CNT-graphene composites. We investigated and compared the sensitivities and piezoresistive properties of sandwich-type pure CNT, pure graphene, and CNT-graphene composite pressure sensors. For all the samples, increase in pressure from 0 to 0.183 kNm−2 results in a decrease in the impedance and direct current (DC) resistance. Sensitivity and percentage decrease in resistance and impedance of CNT-graphene composite were lower than pure CNT while being higher than pure graphene based sample. Moreover, under the same external applied pressure, the sensitivity and percentage decrease in impedance for pure CNT, pure graphene, and CNT-graphene composite were smaller than the corresponding sensitivity and percentage decrease in resistance. The achieved experimental results of the composite sample were compared with simulated results which exhibit reasonable agreement with each other. The deviations of simulated resistance-pressure and impedance-pressure curves from experimental graphs were 0.029% and 0.105%, respectively

Optical Transmission Plasmonic Color Filter withWider ColorGamut Based on X-Shaped Nanostructure

Extraordinary Optical Transmission Plasmonic Color Filters (EOT-PCFs) with nanostructures have the advantages of consistent color, small size, and excellent color reproduction, making them a suitable replacement for colorant-based filters. Currently, the color gamut created by plasmonic filters is limited to the standard red, green, blue (sRGB) color space, which limits their use in the future. To address this limitation, we propose a surface plasmon resonance (SPR) color filter scheme, which may provide a RGB-wide color gamut while exceeding the sRGB color space. On the surface of the aluminum film, a unique nanopattern structure is etched. The nanohole functions as a coupled grating that matches photon momentum to plasma when exposed to natural light. Metals and surfaces create surface plasmon resonances as light passes through the metal film. The plasmon resonance wavelength can be modified by modifying the structural parameters of the nanopattern to obtain varied transmission spectra. The International Commission on Illumination (CIE 1931) chromaticity diagram can convert the transmission spectrum into color coordinates and convert the spectrum into various colors. The color range and saturation can outperform existing color filters.Funding: This project has received funding from Universidad Carlos III de Madrid and the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant 801538

Thin-film carbon nitride (C2N)-based solar cell optimization considering Zn1−xMgxO as a buffer layer

Carbon nitride (C2N), a two-dimensional material, is rapidly gaining popularity in the photovoltaic (PV) research community owing to its excellent properties, such as high thermal and chemical stability, non-toxic composition, and low fabrication cost over other thin-film solar cells. This study uses a detailed numerical investigation to explore the influence of C2N-based solar cells with zinc magnesium oxide (Zn1−xMgxO) as a buffer layer. The SCAPS-1D simulator is utilized to examine the performance of four Mg-doped buffer layers (x = 0.0625, 0.125, 0.1875, and 0.25) coupled with the C2N-based absorber layer. The influence of the absorber and buffer layers’ band alignment, quantum efficiency, thickness, doping density, defect density, and operating temperature are analyzed to improve the cell performance. Based on the simulations, increasing the buffer layer Mg concentration above x = 0.1875 reduces the device performance. Furthermore, it is found that increasing the absorber layer thickness is desirable for good device efficiency, whereas a doping density above 1015 cm−3 can degrade the cell performance. After optimization of the buffer layer thickness and doping density at 40 nm and 1018 cm−3 , the cell displayed its maximum performance. Among the four structures, C2N/Zn0.8125Mg0.1875O demonstrated the highest PCE of 19.01% with a significant improvement in open circuit voltage (Voc), short circuit density (Jsc), and fill factor (FF). The recorded results are in good agreement with the standard theoretical studies.Web of Science111art. no. 9

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

INVESTIGATION OF FANO RESONANCES IN SYMMETRIC AND ASYMMETRIC THREE DIMENSIONAL PLASMONIC NANOSTRUCTURES

Line shaping of localized surface plasmon oscillations in plasmonic nanostructures is a fundamental and application driven research in biomedicine, sensing, energy and optical communication. Such metallic nanostructures with careful arrangement can also support Fano like resonances. These resonances usually crop up from the coupling and interference of a non-radiative mode (dark mode) and a continuum (bright mode) of radiative electromagnetic waves and are distinguished from their Lorentzian counterpart by a distinctive asymmetric line shape and they are typically more sensitive to the geometry of the nanoparticle and changes of the refractive index of the environment. The role of the symmetry breaking in the coupling between the plasmon modes of the individual parts of the layered and neighboring metallic nanoparticles is very important. The reduction of the symmetry of the system relaxes the dipole coupling selection rules resulting in a mixture of dipole and higher order modes. The understanding of this coherent mode coupling will enable the engineering of plasmon line shaping. The focus of this work is to examine theoretically various symmetric and asymmetric plasmonic nanostructures to study the effect of Fano resonances. The proposed nanostructures include spherical, cubical, elliptical, cylindrical and conical geometries with multicomponents as well as nanoparticle pairs (dimer). These nanostructures are designed in such a way that the broad superradiant and narrow subradiant plasmon modes overlap in energy, resulting in a strong Fano resonance in the optical spectrum, which is characterized by a sharp dispersion than the conventional plasmon resonances. Different kinds of new symmetry breaking schemes have been introduced in the layered Fano resonators, which mixes plasmonic modes of distinct angular momenta and provides a set of unique and higher order tunable Fano resonances. The generation of multiple Fano resonances with large modulation depths in the asymmetric Fano resonators are greatly appropriate for multi-wavelength surface-enhanced Raman scattering and plasmon line shaping by modifying the plasmon lines at various spectral locations simultaneously. In addition, the tunable strong Fano like resonance obtained in the conical dimer resonator can be useful for plasmon induced transparency and the local near fields in the “hot spots” are essential for the near field applications. Among all the Fano resonators, the polarization dependent conical Fano resonators have shown striking properties such as high tunability of Fano resonances, as well as the control on resonant electromagnetic field enhancement and scattering direction. Eventually, the optical responses of all the symmetric and asymmetric Fano resonators are well replicated using a mass-spring mechanical analogy and analytical model of Fano line shape. The observations in this thesis may lead to new opportunities to tailor near and far-field optical properties of plasmonic nanoparticles for specific applications, such as high performance surface-enhanced spectroscopy, electromagnetic induced transparency, biosensing, plasmon line shaping, lasing, nonlinear and switching

Fano resonance by symmetry breaking in silver-silica-gold multilayer nanoshells

The multilayer nanoshells symmetry breaking makes otherwise dark higher order modes visible and interacting with the dipole mode. Fano resonance could be accomplished through interferences between these modes. Here we propose a structure based on three shells of different materials (silver, silica and gold) and study the near and far field optical properties. The resonant peaks of extinction and near field enhancement can be tuned and enhanced by offsetting the layers compared to the concentric geometry nanoshell respectively. By displacing the silica shell from the center, higher order dark modes appear in the spectrum predominantly compared to the silver-core and the outer gold-shell offset