Fossil Fuel Consumption Trend and Global Warming Scenario: Energy Overview

Global warming is directly related to the consumption of fossil fuel and corresponding CO2 emission in the atmosphere. We have analyzed available data from various sources for energy consumptions, CO2 emissions, and Earth’s average atmospheric temperature during the period 1970 to 2018. We also analyzed the projected energy consumption data during 2018 to 2050. It is found that human industrial activities between 1970 and 2018 have consumed 385 Gtoe of fossil fuel and emitted1143 Gt of CO2 into the Earth’s atmosphere. As a result, the Earth’s average atmospheric temperature has increased 0.90? between 1970 and 2018. It is found that the projected world total fossil fuel consumption during 2018 to 2050 is 378 Gtoe. We estimate that this 378 Gtoe fossil fuel consumption emits 1122 Gt of CO2 into the Earth’s atmosphere resulting in about another1 °C increase in the Earth’s average atmospheric temperature. We suggest that the global warming is advancing more rapidly, and International communities, scientists and engineers must take appropriate rapid action to save the Earth from devastating consequences

Modeling of enhanced ultraviolet (UV) band detector using Electrostatic Field Effect (ESF)

This project is based on the modeling of Si UV detector by a novel technique to improve its performance. Using linear junction model, doping profile and reverse biased voltage are found to be effective on generation rate, junction capacitance, speed and operating bandwidth. It appears that lower n-doping (body) and higher limit of reverse voltage make it faster response but optimization of doping and reverse biasing are found important to control the transit time. The different passivation layer with harmonized anti reflection layer combination impact are also studied. Different materials such as aluminum oxide (Al2O3), zinc oxide (ZnO), silicon nitride (Si3N4), silicon dioxide (SiO2) and silicon carbide (SiC) and emitter layers effect on photo response have been assessed. By matching the band gap energy and the thickness of those materials, UV absorption inside the active layer can be controlled and eventually photo response is found to be optimized. In this aspect combination of SiO2 and Si3N4 harmonized layers is found promising. Designing PN, P+N, P+iN, NP N+P and N+iP detectors by using harmonized layers, the photo response, quantum efficiency and load/cathode current modeling are also done. A model to evaluate the output current of the cSi W photo detector is performed. The variation of output current as a function of capacitance, response time, junction depth and doping concentration has been analyzed using the model. So such novel techniques for modeling of low cost high photo response and sensitivity UV detector by using cSi are successfully performed

Reduced-stress GaN epitaxial layers grown on Si(1 1 1) by using a porous GaN interlayer converted from GaAs

This paper reports the reduced-stress GaN epitaxial growth on Si (1 1 1) using a porous GaN interlayer which is formed from GaAs layer by a novel nitridation process. Initially a 2 μm thick GaAs layer is grown on a Si(1 1 1) substrate by MBE. Then, a GaN buffer layer of 20 nm thick is grown on the GaAs layer at 550°C in a MOVPE reactor. The GaAs layer capped with the GaN buffer layer is annealed in NH3 to 1000°C. Through this process, a porous GaN layer is formed beneath the GaN cap layer. An epitaxial GaN layer is grown on the GaN buffer layer at 1000°C in the MOVPE reactor. The epitaxial layer grown on the porous-GaN/Si(1 1 1) structure is found to have no cracks on the surface. In contrast, an epitaxial layer grown on the GaAs layer nitrated without a cap layer many cracks are found in the epilayer and the layer is sometimes peeled off from the substrate. It is found that the surface morphology of the GaN/porous-GaN/Si(1 1 1) sample is markedly improved by employing a 40 nm-thick interlayer grown at 800°C in addition to the above processes. A PL spectrum with a high intensity ratio between the excitonic emission and the deep yellow emission is obtained for the GaN/porous-GaN/Si(1 1 1) sample. E2 peak position in Raman scattering spectrum also shows a reduced stress for the GaN epilayers grown on the porous-GaN/Si(1 1 1)

A review on global emissions by e-products based waste: Technical management for reduced effects and achieving sustainable development goals

In the 21st century, a great amount of electrical and electronic waste (e-waste) has accumulated, and the unregulated nature of its disposal and recycling represents a particular hazard in a global context. For the purposes of e-waste management, there must be more emphasis on the scientific processes for recycling, reusing and remanufacturing precious materials. Resource management is related to energy management; therefore, the harvesting of costly materials from e-waste is important for both energy management and sustainable development. At present, a lack of scientific recycling of a significant amount of e-waste is a source of environmental pollution and health hazards that are having a detrimental effect on sustainable development goals. It is necessary to find a process for recovering valuable materials from e-waste with the minimum possible environmental impact. At present, it is essential to modify the process of electrical and electronic products (e-products) becoming e-waste, and the subsequent process of e-waste recycling, in order to lessen the impact in terms of pollution. E-waste scientific recycling initiatives can reduce the environmental impact of the process, which in turn can support a shift from the current linear flow of costly materials to a more sustainable circular flow. Furthermore, internal consumption loss, emissions, and heating loss from e-products are the main factors contributing to the loss of energy efficiency in the process, which in turn contributes to environmental pollution. Promoting green innovation in the manufacturing process of e-products, as well as their reuse, can reduce the environmental impact of e-waste in near future. Both of these pathways are imperative for a less polluted, low-toxic environment and sustainable development. However, the sustainable development initiative of the United Nations Environmental Programme (UNEP) policy framework is the ultimate goal. This is expected to support the management of environmental pollution, maintaining it at an acceptable level, while also preventing hazardous risks to human health. Hence, this review examines the prospects for achievable environmental sustainability through technological developments

Electrical-field activated sintering and forming of micro-components

As the demand for miniature products has increased significantly, so also has the need for these products to be produced in a rapid, flexible and cost efficient manner. The application of electroplasticity shows significant potential to produce the components by using powder materials. Nevertheless, previous research has shown that there are still significant challenges to be met in order to achieve increased relative densification of product samples and simplification of the processes. The process concept in this study comprises the combination of electrical-field activated sintering and forming processes. Therefore, the aims of the research were to develop the process concept for the manufacture of micro-components and to design the die sets along with other tooling for machine setup to enable the forming of micro-components from powder materials. A comprehensive literature review on micro-manufacturing, size effects, powder metallurgy and the electroplasticity process has been conducted. The development of the die sets for the process has been described, followed by a series of experiments. The FE thermal-electrical analysis was also carried out to study the heating flows of the die sets development during the process. In this research, titanium (Ti) and titanium tin alloy (90Ti10Sn) have been selected for the main powder materials tested for both vacuum and open-air process environment by using a Gleeble® 3800 testing system and Projection Welding machine respectively. Meanwhile, for the additional experiment, copper (Cu) has been selected to be tested in the open-air process environment by using a Projection Welding machine with die sets prepared by the Micro-FAST project. Based on the data collected, this efficient process has the potential to produce components with a high relative density of around 98%. Changes of the particles concerning deformation and breaking are crucial in the course of achieving the densification which differs from a conventional sintering process

Low Leakage Current by Solution Processed PTAA-ZnO Transparent Hybrid Hetero-Junction Device

In this work solution processed novel poly-triarylamine (PTAA) organic p-type active layer on inorganic n-ZnO device transparency and electrical properties are investigated under illumination. Low cost organic-inorganic transparent hybrid hetero-junction (HHJ) is a promising candidate for next-generation photovoltaic applications. Greater band gap organic material window layer while inorganic material’s higher thermal stability as HHJ is suitable for detection and photovoltaic applications. However, hetero-interface defects associated leakage current is the key issue of undermining large-area device electrical performance. Hetero-interface defect associated carriers optical absorption limits transparency whereas leakage current density is reliant on physical property and band barrier effect. It is demanded to investigate hetero-device physical stuff and band barrier effect on electrical properties. Novel PTAA is deposited on RF-sputtered inorganic n-ZnO/ITO/glass substrate by spin-coating method. 100 and 60 nm PTAA thin films are deposited with 1,000 and 2,000 revolution per minute (rpm) growth sequence, respectively. PTAA as a transparent p-emitter is shown to absorb incident light beyond visible band, thereby it has promoted excitonic effect. Device I−V characterization carried out at different annealing temperatures and applied voltage. Suitable annealing condition leakage current is shown to reduce nearly 10-4A/cm2 and at higher applied field the greater rectifying I(+)/I(-) ratio is realized. Grain size is shown to increase with annealing effect however; leakage current is remained almost independent of grain size

Photovoltaic technologies photo-thermal challenges: Thin active layer solar cells significance

Massive energy demand and source of energy usages is the key root of global emission and climate change. Solar photovoltaic (PV) is low carbon energy technology currently 3.2% share of global electricity supply. The rapid progress of solar PV is vastly related to increase energy efficiency and lessening of active materials usage. This paper solar PV present significance and most prospective PV materials technical challenges are reviewed for its future advancement. Among the challenges solar energy absorption-related dynamic photo-thermal effect on cells or modules is vital. Transparent passivation contact materials with lower temperature coefficient (TC) and thin active layer resulted in lowering both dynamic photo-thermal outcome and optical to electrical energy gap. Thin active layer minor bulk recombination and sub-band parasitic absorption lessening purpose transparent conductive materials (TCM) based proper band barrier heterointerface is impending. It can optimize desired band absorption and photo-coupling with selective carrier induces greater efficiency. Earlier research though explains it on carrier selectivity prejudice, but how it can lessen the near infrared band optical and associated thermal influence is essential to illustrated. Passivation and TC interrelations hence, field related drift is control over diffusion process loss in advanced bifacial and thin active layer PV technology. Loss lessening pathways thin wafer-based Si, thin film CdTe, organic and perovskite photo coupling with advanced TCM, thus, Si/CdTe and Si/perovskite tandem cells along with OSC building integrated transparent photovoltaic technologies advancement pathways are reported

High Performance Vertically Aligned Electrospun PVP:PC71BM Nanofiber for Organic Solar Cells

This paper is directed towards investigating the characteristic of poly(4-vinylpyrirolidone) (PVPy):[6,6]-phenyl C71 butyric acid methyl ester (PC 71 BM) solar cell for both structural and electrical characteristic by varying the effect of polymer solution concentration and drum rotation speed towards improving the efficiency of Organic solar cell (OSC). PVP:PC 71 BM solar cell with polymer solution concentration of 4wt% and 200rpm drum rotation speed exhibit highest Power Conversion Efficiency (PCE) at 7.8% and 7.5% respectively, a Jsc ranging from 17.28 to 16.90 mA cm -2 and FF value from 63.0 to 62.8% respectively. The added benefit of high absorption properties of PC 71 BM and incorporation of PVP in reducing work function and interfacial resistance further improve the efficiency of OSCs device. This is where PVP:PC 71 BM nanofiber become relevant to the photovoltaic market which lowered production cost with better efficiency without hindering their transparent and flexibility properties for future building integrated photovoltaic application