Advanced Materials and Nano Systems: Theory and Experiment - Part 2

Nanotechnology came into the limelight during the last decade of the twentieth century. It finds immense application in developing nano molecules and nanodevices using molecular, supra-molecular, and atomic level matters. Its role in biomedical engineering is proving crucial. Nanoparticles like silver nanoparticles, gold nanoparticles, etc. have wide implications in biomedicine. Even though there are arguments regarding the side effects, risk factors, removal from the human body, etc., the regular use of nanoparticles has proven cost and time-effective solutions for several human health problems. Due to their small size, nanoparticles have an extended reach in the human body and thus have become effective tools in diagnosis and disease treatment. Most importantly the application of nanotechnology in human health includes drug and protein delivery, treating cardiovascular diseases, cancer, neurodegenerative diseases, ophthalmology, etc. Various nanosystems like dendrimers, nanoshells, nanocrystals, and quantum dots are effectively used to examine and cure cancer and other patients with complex health problems. Despite its wide range of applications in human health and diseases, the toxicological risk assessment of the ecosystem and human health itself is necessary for every newly developed nanomedicine. Thus, interdisciplinary understanding and evaluation of nanotechnology-based solution tools are necessary for its judicial use in human health.

The most prominent aim of this innovative research book chapter has been to study an optimised exploration of characteristics of SWIRL (Short Wave Infra-Red Light) of AlGaAs/GaAs heterogeneous type nanostructure under various GRINSLs (Graded Refractive Index Nano Scale Layers) in advanced bio-based nanotechnological systems. Under this optimised exploration, the simulating performances of SWIRL gain enhancement with wavelengths of light photons for various GRINSLs have been systematically calculated. Other important parameters like SWIRL modal confinement gain with current densities per unit cm2, SWIRL differential gain and parameter of antiguiding with carriers per unit cm3 have been computed. In the innovative investigation through the results, the highest value of SWIRL gain has been achieved at the wavelength ~ 830 nm. The SWIR light of wavelength ~ 830 nm has mostly been utilised in the optimization of a proper combination of higher penetrating abilities and cellular type interactions. Hence, this wavelength’s SWIRL source has also been used in the treatment of wound, pain and various types of sensitive skin diseases by using the FONSCs (Fibre Optic Nano Scale Cables) through the TIRPs (Total Internal Reflection Processes) without any attenuation in dB/Km due to diminished scattering, dispersion and absorptions in the nanotechnological biosciences and medical sciences. Moreover, this SWIRL of wavelength ~ 830 nm has provided the most fabulous role in the proper controlling of inflammation, oedema as well as infections of various bacteria in advanced bio-based nanotechnological systems.

A detailed analysis of electronic band structure of the ScAuSn, LuAuSn and their Superlattice have been performed using the full potential linearized augmented plane waves (FP-LAPW). The exchange-correlation between the electrons was treated with three schemes, generalized gradient approximation (GGA), Trans and Blaha modified Becke-Johnson potential (TB-mBJ) and Spin-Orbit Coupling (SOC) incorporated with GGA. The GGA method reveals an indirect spin-gapless semiconducting nature for LuAuSn, an indirect band gap semiconducting nature for ScAuSn and direct semiconducting nature for their superlattice whereas under mBJ scheme, the band gap values are found to be enhanced. The inclusion of Spin-Orbit Coupling effects in GGA predicts the materials to be semi-metallic. The density of states is mainly dominated by the Sc and Lu atom near the vicinity of Fermi energy level and in the conduction region in ScAuSn and LuAuSn alloys, respectively whereas in superlattice the density of states is mainly dominated by Sc atom with significant contribution from Sn atoms.

Nanotechnology is, in fact, a fairly extensive field of study and research at the moment. Physicists, chemists, biologists, material scientists, engineers, and computer scientists all contributed to its creation. In this paper, we examine how nanotechnology is evolving and growing, as well as how it may be utilised to construct a computer that is smaller, faster, and more trustworthy. In this work, we focus on the top-down and bottom-up manufacturing approaches to nanotechnology, which have a direct impact on current computer design and architecture. Researchers have been driven to enhance and produce a smaller, quicker, and more reliable computers due to the widespread usage of computers and their vast use in the contemporary world. Nanotechnology has the potential to achieve this goal. According to the definition of nanotechnology, it is the design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometre scale atomic, molecular, and macromolecular scale, which results in structures, devices, and systems with at least one novel/superior characteristic or property. Passive nanostructures are the name given to this kind of structure.

In this work, amorphous silicon oxide (a-SiOx:H) and silicon nitride (a-SiNx:H) layers are deposited at a very low substrate temperature of 250oC -300oC by the chemical Vapour deposition technique. Interface charge density (Dit) and fixed charge density (Qf) have been estimated by high frequency (1 MHz) capacitancevoltage measurement on Metal-Insulator–Silicon structure (CV-MIS). The low interface charge density (Dit) reduces the surface recombination velocity. Fixed positive charges (Df) stored in SiOx:H/a-SiNx:H layer forms negative charges at silicon film. The band bending due to negative charges provides a very effective field-induced surface passivation. A significant improvement in efficiency and short circuit current has been observed using developed a-SiOx:H and a-SiNx:H on the front surface of c-Si solar cells. As the refractive index of the films is close to silicon, hence it also acts as an anti-reflection coating (ARC) to reduce optical losses in silicon solar cells.

The nanomaterials are materials of dimensions 1-100 nm. Advanced materials and Nanosystems; synthesis and characterization is an emerging field of research. The day by day modification in synthesis approaches may generate a new synthetic approach. The gradual development in the synthesis techniques from the bulk to nanoparticles synthesis has been reported in this chapter. We are focused on all types of synthesis methods for advanced nanomaterials and the techniques used for nanomaterials characterization. For the Commercial production of nanomaterials, various bottom-up and top-down approaches have been developed during the last two decades. Here, we are trying to summarize the basic principle of solid phase, vapour phase and liquid phase synthetic techniques in detail with a schematic setup.

Nanoparticles of CdS incorporated in Rare Earth doped silica xerogel (RE3+:SiO2) matrix have been prepared by sol-gel method to study its various aspect. The prepared materials have been characterized by physical and optical technique, such as XRD, SEM, TEM and Photoluminescence (PL). We can conclude from TEM that the particle size of the materials 8 nm and an average particle dimension of 5 nm. It is also found consistent with the theoretical calculation performed based on the Scherrer equation and effective mass approximation (EMA) model. The optical properties of these materials depend on various parameters such as dimension and surface characteristics, doping and interaction with the surrounding environment. Enhancements of Rare Earth (RE) ions luminescence have been observed with the presence of CdS NPs in RE3+:SiO2 matrix. A twenty time more intense dominating orange peaks (616 nm) from the characteristic peak of Eu3+ ions are observed for CdS/Eu3+:SiO2 matrix compared to the sample without CdS NPs. The efficient energy transfer (ET) from CdS NPs to RE ions is primarily responsible for this boost in the luminescence intensity. The emission intensity in PL spectra decreases with raise in the concentration of CdS NPs. With an increase in CdS NPs concentration in RE3+:SiO2 matrix, the emission intensity decreases possibly due to the increase in the concentration of “oxygen vacancy ”and “Si hanging” in the matrix of the silica xerogel. Thus, photoluminescence properties of the material are greatly influenced by site symmetry and hence the concentration of dopant ions.

We present first-standards estimations on Fe, Nd, and SmCo5 utilizing the self-predictable maximum capacity linearized increased plane wave (FPLAPW) strategy. The attractive snapshots of Fe, Nd, and Smco5 were determined utilizing the WIEN2K code. The minutes for BCC Fe and HCP Nd are 2.27μB and 2.65μB separately in great concurrence with test esteems. For Smco5, we efficiently study the impact of considering the twist circle coupling and Coulomb connections in the Sm f shell on the attractive properties, electronic construction, and twist thickness maps. The determined attractive second and magneto-crystalline anisotropy like anisotropy are in acceptable concurrence with test esteems. The twist thickness maps in the (001) plane show that the impact of the twist circle coupling on the twist thickness design of Sm particles is more grounded than that of Coulomb connection. We additionally study the impact of the polarization heading on the energy groups by looking at the highlights of band structure when the charge bearing is along or opposite to the c-axis. The determined outcomes are in acceptable concurrence with the exploratory information.

Sulfide-based semiconductor nano photocatalysts like ZnS and CdS of different particle sizes were prepared by chemical method. These photo catalysts show an excellent photo catalytic activity in the visible region due to their appropriate energy bandgap (Eg). Multiwalled carbon nanotubes (MWCNTs) intercalated sulfide-based photocatalysts like ZnS/MWCNTs and CdS/MWCNTs composites enhance photocatalytic response in comparison to ZnS and CdS NCs. The photocatalytic activity of MWCNTs intercalated ZnS and CdS composites were studied via decomposition of organic pollutant. The obtained particle size of the CdS, ZnS, MWNT/CdS, and MWCNT/ZnS crystals were found to be 32.0 nm, 8.48 nm, 38.5 nm, and 13.18 nm, respectively. The FTIR characteristics of MWCNT/ZnS and MWCNT/CdS composites represent bands at 1637 and 3313 cm-1 in presence of methylene blue. The intense band at 1637 cm-1 could be the stretching vibrations of the C=O group and the other intense band at 3313cm-1 was assigned to the stretching vibration of O-H group. The reduction in optical band gap for MWCNTs/CdS (2.39eV) over CdS (2.44eV) and MWCNT/ZnS (3.77 eV) over ZnS (3.88 eV) was observed. Enhancement in photocatalytic activity was verified along with pseudo-first-order chemical kinetics.

New photovoltaic energy technologies are helping to provide ecologically acceptable renewable energy sources while also lowering carbon dioxide emissions from fossil fuels and biomass. Organic photovoltaic (OPV) technology is a novel type of solar technology based on conjugated polymers and small molecules. These solar cells have enticed triable attention in recent years due to their potential of providing mechanical flexible, light weight, low cost and environmental friendly solar cells with highly tunable electrical and chemical properties. In particular, bulk-heterojunction organic solar cells (OSCs) made up of a blend of a p-type conjugated polymer as a donor and an n-type semiconductor as an acceptor is thought to be a viable method. The fundamental physics of OSCs, their operating mechanism, novel materials used and device architectures are discussed in this chapter. The technological development for large-area fabrication and the studies on stability issues of the flexible OSCs will be the main focus of the researchers in the next step. The chapter also reviews the present state of OSC production and the problems that it faces, as well as issues of stability and deterioration.

In the present research work, melt-quench technique was employed for synthesis of Nd2O3 doped lithium borosilicate glasses having general system 30Li2O- (70-x) [1/7SiO2:6/7B2O3]-xNd2O3. Electrical conductivity of produced samples was tested in frequency band of 2mHz to 20MHz at 423K to 673K, using Impedance Analyser. Impedance data was used for scaling which shows that the process of conduction is based on the composition and not on the temperature. The inclusion of neodymium oxide in the lithium borosilicate glass affects molar volume, density and various physical properties like Ion concentration, ionic radius. The electrical modulus data obtained from impedance analyser was utilized to study relaxation behaviour of the samples. In the temperature band, 423-673 K, the variance of the dielectric loss (Tan δ), dielectric constant (ε’) and ac conductivity (σ’) with frequency was measured using impedance spectroscopy and discussed at length.

Lung cancer is one of the major classes of cancer affecting men. Capmatinib is developed and approved as a medicine to fight non-small lung cancer. Even though the compound is developed for the management of cancer, it may be of several other applications. To tune the property of molecules to fit diverse functions, the study of the electronic structure and other quantum mechanical properties is very important. Literature survey indicates that the detailed structure and reactivity profile of this compound was not reported. We use molecular modeling using DFT and TD-DFT methods using B3LYP/CAM-B3LYP/aug-cc-pVDZ level to study the structure, reactivity, and other Physico-chemical properties of this compound. The optical properties of the compound are compared with standard materials. Different useful indices from molecular wave function analysis present the reactivity and stability of the compound in detail. A qualitative study of non-covalent interactions was also reported along with many useful local information entropy studies, which showed that the molecule is stable with low uncertainty of electrons in spatial distribution.