Large electromagnetic field enhancement in plasmonic nanoellipse for tunable spaser based applications.

We theoretically demonstrated a class of plasmonic coupled elliptical nanostructure for achieving a spaser or a nanolaser with high intensity. The plasmonic ellipse is made up of gold film substrate. The proposed structure is then trialed for various light polarizations, moreover, a simple elliptical nanostructure has been chosen primarily from which different cases have been formed by geometry alteration. The structure supports strong coupled resonance mode i.e. localized surface plasmon (LSP). The localized surface plasmon resonance (LSPR) of the investigated system is numerically examined using the finite-element method (FEM). The calculations showed that the LSPR peaks and the local field intensity or near field enhancement (NFE) of the active nanosystem can be amplified to higher values by introducing symmetry-breaking techniques in the proposed ellipse and its variants. The coupled nanostructure having different stages of wavelengths can be excited with different plasmonic resonance modes by the selection of suitable gain media. In addition, a small-sized nanolaser with high tunability range can be developed using this nanostructure. The spaser phenomena are achieved at several wavelengths by changing light polarization and structure alteration methods. Giant localized field enhancement and high LSPR values enable the proposed model to be highly appealing for sensing applications, surface-enhanced Raman spectroscopy, and much more.

Novel perovskite solar cell with Distributed Bragg Reflector.

This paper reports numerical modeling of perovskite solar cell which has been knotted with Distributed Bragg Reflector pairs to extract high energy efficiency. The geometry of the proposed cells is simulated with three different kinds of perovskite materials including CH3NH3PbI3, CH3NH3PbBr3, and CH3NH3SnI3. The toxic perovskite material based on Lead iodide and lead bromide appears to be more efficient as compared to non-toxic perovskite material. The executed simulated photovoltaic parameters with the highest efficient structure are open circuit voltage = 1.409 (V), short circuit current density = 24.09 mA/cm2, fill factor = 86.18%, and efficiency = 24.38%. Moreover, a comparison of the current study with different kinds of structures has been made and surprisingly our novel geometry holds enhanced performance parameters that are featured with back reflector pairs (Si/SiO2). The applied numerical approach and presented designing effort of geometry are beneficial to obtain results that have the potential to address problems with less efficient thin-film solar cells.

Thickness Optimization of Thin-Film Tandem Organic Solar Cell.

The polymer solar cells also known as organic solar cells (OSCs) have drawn attention due to their cynosure in industrial manufacturing because of their promising properties such as low weight, highly flexible, and low-cost production. However, low η restricts the utilization of OSCs for potential applications such as low-cost energy harvesting devices. In this paper, OSCs structure based on a triple-junction tandem scheme is reported with three different absorber materials to enhance the absorption of photons which in turn improves the η, as well as its correlating performance parameters. The investigated structure gives the higher value of η = 14.33% with Jsc = 16.87 (mA/m2), Voc = 1.0 (V), and FF = 84.97% by utilizing a stack of three different absorber layers with different band energies. The proposed structure was tested under 1.5 (AM) with 1 sun (W/m2). The impact of the top, middle, and bottom subcells' thickness on η was analyzed with a terse to find the optimum thickness for three subcells to extract high η. The optimized structure was then tested with different electrode combinations, and the highest η was recorded with FTO/Ag. Moreover, the effect of upsurge temperature was also demonstrated on the investigated schematic, and it was observed that the upsurge temperature affects the photovoltaic (PV) parameters of the optimized cell and η decreases from 14.33% to 11.40% when the temperature of the device rises from 300 to 400 K.

Gratitude and Its Conceptualization: An Islamic Perspective.

Employees constitute an integral part of every organization, and their behaviours cultivate success or failure for the entire industry. Each organization should be cognizant of its employees' behaviours that can be translated through their behavioural outcomes. One of such outcomes is the level of gratitude (Shukr in Islamic perspective) that can be conceptualized further by establishing its link with employees' social or pro-social behaviours using lens of Islamic philosophy. The literature from the perspective of Holy Quran and Sunnah (Prophet's practices) suggests that a good number of employees working in different industries have an element of dissatisfaction reflected through various factors including lack of Shukr (gratitude). This calls for a conceptual undertaking along with its subsequent empirical assessment as the former needs a robust and holistic understanding before proceeding to the latter. The study begins with a strong conceptualization by comparing conventional and Islamic perspective of Shukr and to synthesize key factors which can later help in scale development of Shukr. After a careful comparison between conventional and Islamic viewpoints, three components (dimensions) of Shukr were conceptualized such as Shukr bi'l-qalb (gratitude expressed by inner feelings), Shukr bi'l-lisan (gratitude expressed by tongue) and Shukr bi'l-badan wa'l-arkan (gratitude expressed by body and limbs). This conceptualization can potentially serve as a tool to examine the level of contentment, employees exhibit at workplace which eventually leads to life and job satisfaction.