Herein, this work scrutinises the charge transport properties of solution-processed methylammonium lead iodide (MAPbI 3 ) perovskite-based hole only device through the DC current-voltage and AC impedance spectroscopy analysis. The device shows a significant increase in the current levels under illumination. Key diode parameters were estimated from the dark I-V curves. The dominance of Ohm's law at low bias, space charge limited conduction (SCLC) followed trap controlled SCLC at higher applied bias was observed from charge transport analysis. From the region dominated by the trap free SCLC, the hole mobility of 4.02 × 10 -6 cm 2 V -1 s -1 inside the perovskite layer was extracted. The measured impedance spectrum was analysed by fitting it with the equivalent circuit model, and the various physical parameters, such as charge transport resistance, recombination resistance and associated capacitance were approximated for the device.

In this work, gold nanoparticles have been prepared using the leaf extract of Eupatorium odoratum assisted with microwave irradiation. The role of pH on the synthesis of gold nanoparticles has also been studied. At higher value of pH, size of nanoparticles got highly diminished, going below 10 nm. A probable mechanism of formation of such small nanoparticles has been proposed in this Letter. The effects of different parameters such as reaction time, temperature and pH variation on the final morphology of gold nanoparticles have been investigated. The characterisation of the samples has been carried out by transmission electron microscope, UV–Vis absorption spectroscope, Fourier transform infrared spectroscope and zeta potential analysis. Further, a comparative study of catalytic activity of gold nanoparticles of two different sizes was performed by monitoring the reduction of 2,4,6-trinitrophenol. Experimental study showed that smaller nanoparticles are more efficient in their catalytic activity than their larger counter parts. The consistency in sizes and shapes, higher stability and rapid synthesis are the major advantages of this synthesis method. Thus, this procedure of synthesis of gold nanoparticles may offer an attractive alternative to the existing ones and opens a full range of possibilities for various analytical applications.

Cobalt phosphide/reduced graphene oxide (Co2 P/RGO) nanocomposites were synthesised successfully via a facile in-situ solvothermal method. Co2 P nanoparticles with a mean size of 80 nm anchor uniformly and firmly on the surface of RGO nanosheets, which not only avoid the aggregation of Co2 P nanoparticles, but also prevent the restacking of RGO nanosheets. Used as a degradation agent, the as-prepared composites exhibit superior adsorption degradation activity for various organic dyes. As an anode material for Li-ion battery, the Co2 P/RGO composites also show good electrochemical properties and its initial discharge specific capacity of the as-prepared composites can achieve to 900 mAh/g. The reason might be attributed to the interfacial interaction and the effective combination of Co2 P nanoparticles with RGO nanosheets.

Colloidal stability of magnetic fluids with desirable magnetic properties plays an important role in cooling applications in power transformers. Colloidal stability largely depends on nanoparticles’ characteristics and quality of their dispersion in transformer oil. In this work, a detailed discussion on the development of synthesis protocols for Mn1−x Znx Fe2O4 (MZ) fluids is described. The effect of degree of Zn-ion substitution under an optimised condition of MZ nanoparticles on the dispersion quality of MZ fluids and their magnetic properties are investigated in this work.

High-k spacer and gate insulator materials have been exhaustively studied nowadays for the enhancement of electrostatic control and reduction of short-channel effects in scaled devices. The work presents a high-performance and charge trap tolerant FinFET module at 10 nm gate length. Dual layer gate insulator (inner low-k and outer high-k) introduces to reduce charge trapping from the channel and outside into the gate oxide. It reduces the gate leakage current by 51.6% compared to conventional FinFET. Further, they demonstrate single charge trapping (SCT) induce effects and proposed optimised high-k spacer width of the SCT tolerant design. SCT analysis is presented in different high-k spacer materials and back-gate voltages. Process variation sources such as line edge roughness and line width roughness are also analysed for the circuit design.

The novel composite structure of TiN nanoparticles enclosed by graphite carbon coating (TiN/C) has been successfully prepared through a facile one-step solid state method under N2 atmosphere using the TiO2 powder and melamine as raw materials. TiN nanoparticles with size ranging from 12 to 15 nm are covered by filmy graphite carbon layer, and their electrocatalytic properties towards oxygen reduction are further investigated. Benefiting from the surface chemical bonding of oxide and oxynitride components, TiN/C nanocomposite exhibit a considerable catalytic activity. The current density of TiN/C nanocomposite (4.65 mA cm−2 at 0.2 V) is comparable to that of commercial Pt/C catalyst, in spite of a little more negative gap in onset potential. Moreover, the TiN/C nanocomposite has excellent long time durability and methanol tolerant performance with the protection of graphite carbon coating.

In this research work, colloidal silver nanoparticles were successfully produced via an electrolysis method and their antibacterial activity was evaluated. This study aims to determine the optimum concentration of colloidal silver nanoparticles to produce an effective inhibition zone for Escherichia coli bacteria growth. Based on the results obtained, the applied current and reaction times during the electrolysis played a crucial role in determining the colloidal silver nanoparticles’ concentration (ppm). It was found that a minimum content of colloidal silver nanoparticles (0.02 ppm) was required to perform the 0.1 mm inhibition zone diameter on agar medium spread with E. coli bacteria. Interestingly, high concentrations of colloidal silver nanoparticles could exhibit high conductivity (µS/cm) as well as the high intensity of the maximum plasmon peak from the UV/vis absorption spectra at about 390 nm. In conclusion, this research work revealed the destruction of the cytoplasmic membrane and the rupture of the internal organisation of E. -coli bacteria, leading to the leakage of the cytoplasmic contents and cell death after having contact with sufficient concentration of colloidal silver nanoparticles.