A Study on Carbon Capture and Storage and Its Feasibility in Energy-Environment Technologies.

Carbon capture and storage (CCS) has the potential to play an important role in managing global warming in the near future. Herein, we define the entire energy cycle from energy production to utilization considering energy-environment technologies and describe the technical classification and brief technical principles of CCS technology. In addition, we evaluate data from actual scenarios and costs of various indicators established from diverse reports published by reliable institutes on various energy-environment technologies. Finally, the economic feasibility of CCS is determined compared with that of fossil fuel power plants and renewable energy generation in terms of carbon credit for global trading. This techno-economic analysis and systematic review lays the groundwork for comprehensive research toward understanding energy-environment technologies by establishing scenarios in terms of cost and data analysis that can provide an objective approach.

Vastly enhanced photoresponsivities of phase-controlled tin sulfide thin films.

Herein, we reveal extraordinary enhancements in the photoresponsivities of tin sulfide (SnxSy) grown on SiO2/Si wafers through post-phase transformations induced by electron beam irradiation (EBI) and crystallization. Amorphous SnxSy thin films were formed by room-temperature sputtering, and as-deposited films were subsequently transformed into hexagonal SnS2 and orthorhombic SnS phases by EBI at 600 and 800 V respectively, for only one minute. The use of a low-energy electron beam was sufficient to fabricate a SnxSy photodetector, with no additional heating required. Less than 10 nm thick SnxSy films with well-defined layer structures and stable surface morphologies were obtained through EBI at 600 and 800 V. The resulting phase-controlled SnS thin-film photodetector prepared using 800 V-EBI exhibited a 40 000-fold increase in photoresponsivity; when illuminated by a 450 nm light source, the active SnS-layer-containing photodetector demonstrated a photoresponsivity of 33.2 mA W-1.

Exceptionally Uniform and Scalable Multilayer MoS2 Phototransistor Array Based on Large-Scale MoS2 Grown by RF Sputtering, Electron Beam Irradiation, and Sulfurization.

Two-dimensional molybdenum disulfide (MoS2) has emerged as a promising material for optoelectronic applications because of its superior electrical and optical properties. However, the difficulty in synthesizing large-scale MoS2 films has been recognized as a bottleneck in uniform and reproducible device fabrication and performance. Here, we proposed a radio-frequency magnetron sputter system, and post-treatments of electron beam irradiation and sulfurization to obtain large-scale continuous and high-quality multilayer MoS2 films. Large-area uniformity was confirmed by no deviation of electrical performance in fabricated MoS2 thin-film transistors (TFTs) with an average on/off ratio of 103 and a transconductance of 0.67 nS. Especially, the photoresponsivity of our MoS2 TFT reached 3.7 A W-1, which is a dramatic improvement over that of a previously reported multilayer MoS2 TFT (0.1 A W-1) because of the photogating effect induced by the formation of trap states in the band gap. Finally, we organized a 4 × 4 MoS2 phototransistor array with high photosensitivity, linearity, and uniformity for light detection, which demonstrates the great potential of 2D MoS2 for future-oriented optoelectronic devices.

Eutectic Bonding Utilizing Radio Frequency Induction Heating for Fabricating Vertical Light-Emitting Diodes.

Vertical light-emitting diodes (VLEDs) have attracted considerable attention owing to their improved thermal, electrical, and optical performance compared to conventional LEDs. To fabricate VLEDs, a bonding technique is required following laser lift-off. Eutectic bonding techniques are preferred owing to their low-heat mechanism and production safety. However, the conventional resistance heating method for eutectic bonding process, the extremely longer process time becomes a problem such as cost rise, wapage. In this study, the thermal efficiency was measured according to the diameter of the coil in order to optimize the eutectic bonding of the RF induction heating method in order to solve this problem. We confirmed that successful eutectic bonding is possible with less than 30 min processing using Sn-Glass. In addition, Au (20 wt%)/Sn (80 wt%) alloy, a mainly used the eutectic bonding interlayer material for VLEDs, can also be used as an interlayer to provide void-free eutectic bonding in less than 30 min.

Hybrid Electrodes of Carbon Nanotube and Reduced Graphene Oxide for Energy Storage Applications.

The choice of electrode materials in lithium ion batteries and supercapacitors is important for the stability, capacity, and cycle life of the device. Despite its low capacity, graphite has often been used as an electrode material due to its inherent stability. Due to an increasing demand for large-capacity energy storage systems, there is also a demand for the development of large-capacity Li ion batteries and supercapacitors. Therefore, carbonaceous materials like graphene and carbon nanotubes (CNTs), which have high stability as well as excellent electrical conductivity and mechanical strength, are receiving attention as new electrode materials. Recently, starting from simply applying graphene and CNTs as electrode materials and progressing to the development of hybrid materials, there have been increasing research efforts in enhancing the performance of Li ion batteries and supercapacitors through the use of carbonaceous materials. This paper will discuss new composite materials and electrode structures that use graphene and CNTs for applications in Li ion batteries and supercapacitors.