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NMOS-based gas sensors are a strong detection technique for studying elevated environmental NO2 concentration and its impact on the plant ecosystem.

The synthesis of nanomaterials and nanostructures is an important aspect of nanoscience and nanotechnology. New physical properties and applications of nanomaterials are only possible when nanostructured materials are made available with desired size, shape, morphology, crystal structure, and chemical composition. For this reason, in order to explore novel physical properties and phenomena to realize potential applications of nanomaterials, the ability to fabricate and process nanomaterials is the foremost cornerstone in the research and development of nanotechnology. This chapter provides a clear and concise understanding with detailed review work on the synthesis of nanomaterials through a kinetic approach using well-known Stokes' law for a free body falling in a quiescent and viscous fluid.

The current study investigates the fabrication of semiconducting molybdenum disulfide thin film using reactive magnetron sputtering technique at 300 °C for thin film transistors (TFTs) application. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Field emission-scanning electron microscopy (FE-SEM) techniques were used to identify the structural, elemental compositional and morphological properties of the synthesized thin film. XRD and Raman data confirm the growth of hexagonal structure and FE-SEM images indicate the vertical aligned layered morphology. The fabricated TFT demonstrates excellent performance in terms of field-effect mobility of 24.17 cm2 V−1 s−1 and a high Ion/Ioff ratio of the order of 106.

With an advanced understanding of cathode materials in Li-ion batteries (LiBs) and supercapacitors, it has been observed that the surface structures of cathodes play an important role in these devices and significantly affects the whole system's performance e.g. maintain the structural stability and material's conductivity. Various approaches are being applied to enhance the electrochemical performances of batteries and supercapacitors e.g. doping of transition metal ions, synthesis of composite materials, synthesis of nanomaterials, and surface modification of materials. Among these techniques, surface modification of the electrode materials is widely used because of ease of synthesis and cost effectiveness. In the present article, the recent advancements in surface modifications of the energy storage electrode materials and their electrochemical performances are summarized. First, coating strategies and their effects on cathode are discussed and then the current research progress focusing on the surface coating materials are covered. At last, the challenges faced are discussed to improve the performances of cathode materials. In this study, we are presenting that the selection of coating materials and technologies plays a vital role in the advancement of cathode materials.

In the present work, we synthesize molybdenum disulfide (MoS2) thin films on the soda lime glass substrate (SLG) by reactive sputtering of molybdenum target in the Ar–H2S atmosphere at different sputtering power. The structure and the surface morphology of the reactive magnetron sputtered MoS2 thin films have been investigated using the X-ray diffraction technique (XRD), Raman spectroscopy, and Field emission scanning electron microscopy (FE-SEM). X-ray photoelectron spectroscopy (XPS) and Energy dispersive X-ray analysis (EDX) provides the chemical information and elemental composition of MoS2 thin films, respectively. The optical properties of reactive sputtered deposited MoS2 thin films were analyzed by absorption and photoluminescence spectroscopy (PL) while the optical constants were determined using spectroscopic ellipsometry. XRD results exhibit the hexagonal crystal structure of reactive sputtered MoS2 thin films. FE-SEM images reveal the formation of nanoworms in reactive sputtered deposited MoS2 thin films. EDX confirms the homogeneity; uniformity and good atomic percentage of Mo and S in the MoS2 thin films. Absorption spectra confirm the indirect bandgap of as-grown MoS2 thin film. PL spectra give an idea about defect formation whereas ellipsometric measurements determine the variation of optical constants with a photon energy of the as-deposited thin film of MoS2 which suggests its application for future optoelectronic devices.

This study presents the effect of low energy (120 KeV) O-ions implantation on the photosensitivity of PbS thin films by vacuum thermal evaporator (VTE). The crystallite size (D) of PbS films decreased from 32.8 nm to 17.4 nm and the bandgap (E g) increased from 1.61 eV to 1.76 eV as the fluence increased from 0.5 × 1016 ions cm−2 to 1.5 × 1016 ions cm−2. The PL spectra of O-ions implanted PbS thin films showed a dominant peak at 381 nm regardless the fluence of implantation. The photocurrent sharply increased by the implantation of O-ions (0.5 × 1016 ions cm−2) due to the creation of ‘shallow traps’ in the forbidden gap of PbS thin films under illumination of visible light (100 mW cm−2). The highest photosensitivity of O-ions implanted PbS thin films was observed due to the creation of proper traps for the photoconduction for the particular dose of 0.5 × 1016 ions cm−2.