This PDF file contains the front matter associated with SPIE Proceedings Volume 11561, including the Title Page, Copyright information, and Table of Contents.

In this work, we have analyzed the behavior of optoelectronic characteristics i.e. internal quantum efficiency (IQE) by the influence of piezoelectric field. This effect was not considered in widely reported models such as the Standard ABC model, Rate equation model, and phase-space-filling model. In Gallium Nitride (GaN)-based light-emitting diodes (LEDs), the active region is comprised of InGaN/GaN layers. For the emission of green light, high composition of indium is needed in InGaN layer. As a result, the lattice mismatch between GaN and InGaN layer is highly dominated, which leads to strong piezoelectric field. Our proposed calculation by including piezoelectric field shows better agreement with the experimental IQE of green LED. Meanwhile, we have proposed a single quantum well (SQW) device structure with reduced piezoelectric field as compared to the conventional structure.

New group of 2-dimensional materials such as MXene, Ti₃C₂, containing transition metals creating a hexagonal structure with the atoms of carbon that arouse growing attention these days, the production of doped MXene sheets is reported in this work. For numerous materials, rare earth metals were used primarily as dopants to improve their properties for decades. The study reports on cerium (Ce⁺³) doping synthesis in the MXene (Ti₃C₂) sheets and its surface, optical and structural observation. MXene sheets of Ce-Ti₃C₂ have been fabricated by using easy low-cost sol gel technique. X-Ray Diffraction (XRD) was used for study of nanosheet phase and crystallinity. Crystallite sizes have been calculated by the formula of Debye-Scherer. The sample surface morphology was analyzed with the help of Scanning electron microscopy (SEM). Analysis of the UV-Vis curve to find the bandgap reduction in nanosheet. FTIR has been used to investigate the MXene layer molecular bonding of surface. Cerium (Ce⁺³) atoms were successfully doped into the sheets, slightly tuned bandgap, the parameters of the lattices indicate minor change in length of c- LP, verifying modification of the Ti⁺⁴ atoms with Ce⁺³ atoms.

Climate change and increase population are the major causes of insecurity for food production. Climate change also effective agriculture like temperature rising, arid environment, unconditional weather changing and clean water deficiency. In cold areas, winter farming has been carried out on glass based structural or transparent greenhouse. These types of greenhouse are not suitable to summer farming in South Asian countries because sunlight radiations cause hazard greenhouse effect (Increase temp. humidity and oxygen, carbon diffusion rate). Recently, Smart farming in agriculture provide great flexibility to control environment factors (temperature, moisture, and water irrigation and gasses. Smart agriculture depending upon controlled artificial generated environment like as greenhouse farming and hydroponic culture (vertical farming). In proposed study, smart structure with smart control has been designed to control possible factors which are relevant to optimal plants health. Smart control inducing by smart sensor based on intelligent control system (environmental sensors with processing devices) and android application use for analysis of current condition of smart green house. The proposed greenhouse has been made by using wooden air ventilations transpiration sheet structure. This structure evaporates heat and isolated harm sunlight radiation for summer farming in arid areas. This isolation sheets save electric energy for maintaining temperature and spectrum of light. Intelligent Smart farming is necessary for better future of the nation and also better than traditional farming due to reduction of human interaction and automation system.

In this article density functional theory (DFT) approach is utilized to study the crystal structure and optoelectronic properties of the double perovskites Ba₂MM′O₆ (M= Sc, Y, La; M′= Nb, Ta) in cubic phase with space group Fm-3m (No. 225). Generalized gradient approximation along with modified Becke-Johnson exchange potential is used to investigate the optoelectronic properties of these transition metal based compounds. The calculated electronic band profiles show that all these oxides are wide and direct bandgap semiconductors. The bandgaps of the oxides ranges from 3.8 to 4.7 eV. Optical properties demonstrate many aspects due to their potential applications as dielectric materials and in optoelectronic devices.

This study is related to two electrode, single cell, graphite-stainless steel electrode, aqueous electrolyte battery. In this era of electric cars, batteries are key component. Metal-air batteries are considered to be suitable for this purpose, but quick after assembling metal electrode battery, an oxide layer is developed prohibiting the further oxidation of metal and hence potential drops to zero. To solve this problem, Metal is replaced by non-oxidizing stainless steel cathode and the graphite sheet is used as anode. The system used consists of a beaker filled with Ferrous Sulphate electrolyte and electrodes immersed in it. A constant current, constant voltage source was for initial charging. Battery was allowed to charge for a couple of minutes and then disconnected to study the temporal changes in voltage drop. The voltage developed across the terminals varied from 1 volt to fully discharge whereas as current rating with full potential was one ampere. The system behaves as battery because during the process of charging, flexible natural graphite foil is decomposed to form graphite/graphene layers running into electrolyte and deposited on electrode as. In this way both charging and discharging process were useful. Graphene, the end product of this process is very useful, environmental- friendly and recyclable material. Furthermore, the graphene rechargeable battery can be compacted to a small size.

In this study, thermal properties of R134a/TiO₂ and R513a/TiO₂ such as thermal conductivity, density and dynamic viscosity , specific heat and convective heat transfer coefficient investigated. The TiO₂ nanoparticles are average size of 10 nm and volume concentration from 1% to 10%. The theoretical analyses show that the thermal properties of R513a/TiO₂ nanorefrigerant are better than R134a/TiO₂ nanorefrigerant.

Different cloaking technologies exist but have not yet been practically applicable as a phenomenon in itself and a wide variety of applications owing to the treatment of the phenomenon initially with a mathematical approach, hence turning the interesting phenomenon into a boring, cumbersome and an impractical one by neglecting the feasibilities involved at a particular yet crucial stage. This paper discusses the phenomenon of paraxial ray optical cloaking with a practical approach, void of heavy mathematical equations. The technique elaborated in this paper is not dependent upon the distance between the pairs of lenses since lenses with the same focal lengths have been used in the experiment, contrary to which was done in prior researches and experiments. It is noted that the perfect paraxial optical ray cloaking is observed at a very low cost when compared to other experimental setups. This low cost helps in setting up experiments for the education sector. The experiments for the achievement of the invisibility can be performed by students of even secondary and higher secondary standards due to the affordability. However, it is also observed that this experimental setup is currently not applicable for hiding or 'cloaking' objects larger in size, but larger objects can be hidden or 'cloaked' if the diameter of the lenses is increased.

The electronic, magnetic and optical properties of pure and thulium (Tm) doped ZnO have been investigated by using first principle method. We applied Generalized Gradient Approximation (GGA), GGA+U where U is Hubbard parameter and Tran-Blaha modified Becke-Johnson (TB-mBJ) for exchange correlation potential. The band gap value calculated by TB-mBJ is 2.79 eV, which is in good agreement with the experimental value. Then we doped ZnO with Tm using a super cell of 1× 1 × 2 (16 atoms) with 25% atomic concentration of Tm. It is found that the Tm doped ZnO system became anti-ferromagnetic (AFM) in ground state for Far configuration, whereas for Near configuration, the system of Tm-doped ZnO is ferromagnetic (FM) degenerate semiconductor. It is observed from density of states that there is spin polarization in states of Tm-doped ZnO so it has net magnetic moment. The formation energy is also increased with the decrease of the distance between the atoms of Tm.

Structural, dielectric and electrical properties of polycrystalline double perovskite oxides La₂BMnO₆ (Where B= Cr, Fe, Co, Ni, Cu, Zn) were prepared by auto combustion sol-gel method. The characterization of samples via X-ray reflects single phase in present series. X-ray diffraction pattern of all samples reveal monoclinic structure with space group P2₁/n except Cu which shows orthorhombic symmetry with Pbnm space group. The crystallite size (𝐷) was calculated by Scherrer formula and Williamson hall analysis. Frequency dependent dielectric properties measured at various temperatures. Dielectric constant (ε′) and loss tan δ decreases with frequency. AC conductivity (σ_ac) increases as function of frequency shows semiconducting nature. I-V characteristic curve shows increase in current with rise in temperature. The DC resistivity (ρ_𝑑𝑐) shows negative temperature coefficient behaviour. It is confirmed that results in case of copper and chromium fitted well by small polaron hopping (SPH) model and for cobalt variable range hopping (VRH) of small polaron was observed whereas for Zn, Ni and Fe follows variable range hopping model.

In the present work, BFO doped with Lanthanum has been synthesized by the Sol-Gel method. The wet chemical method is found suitable for the BFO synthesis as it is a low-temperature synthesis method and avoids evaporation of Bismuth from the BFO. The synthesized Bi_1-xLa_xFeO₃ (x = 0.0, 0.10, 0.15, 0.20, 0.25, 0.30) samples have been characterized by X-ray diffraction for structural analysis. The electrical properties of samples have been observed by measuring the room temperature and temperature-dependent dc electrical resistivity, and activation energy. The XRD patterns reveal almost a single crystalline phase of all the samples with only a few traces of an additional phase of Bi₂Fe₄O₉. The Lanthanum doped BFO is found to have a pseudo-cubic rhombohedral perovskite-type structure having space group R3c. The grain size calculated using the Scherrer formula is 27 nm for un-doped BFO and is found La-concentration dependent. The dc resistivity measurements reveal the semiconducting behavior of samples; resistivity increases on increasing the Laconcentration in BFO while decreases on increasing temperature. The La³⁺ ion which replaces Bi³⁺ in BFO stabilizes the perovskite structure by preventing Bi³⁺ loss due to volatilization and removes charge vacancies; thus improving the electrical properties of BFO.