[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Conductometric semiconducting metal oxide gas sensors have been widely used and investigated in the detection of gases. Investigations have indicated that the gas sensing process is strongly related to surface reactions, so one of the important parameters of gas sensors, the sensitivity of the metal oxide based materials, will change with the factors influencing the surface reactions, such as chemical components, surface-modification and microstructures of sensing layers, temperature and humidity. In this brief review, attention will be focused on changes of sensitivity of conductometric semiconducting metal oxide gas sensors due to the five factors mentioned above.

Metal oxide gas sensors: Sensitivity and influencing factors

Transparent conductors as solar energy materials: A panoramic review

Metal oxide gas sensors are predominant solid-state gas detecting devices for domestic, commercial and industrial applications, which have many advantages such as low cost, easy production, and compact size However, the performance of such sensors is significantly influenced by the morphology and structure of sensing materials, resulting in a great obstacle for gas sensors based on bulk materials or dense films to achieve highly-sensitive properties Lots of metal oxide nanostructures have been developed to improve the gas sensing properties such as sensitivity, selectivity, response speed, and so on Here, we provide a brief overview of metal oxide nanostructures and their gas sensing properties from the aspects of particle size, morphology and doping When the particle size of metal oxide is close to or less than double thickness of the space-charge layer, the sensitivity of the sensor will increase remarkably, which would be called "small size effect", yet small size of metal oxide nanoparticles will be compactly sintered together during the film coating process which is disadvantage for gas diffusion in them In view of those reasons, nanostructures with many kinds of shapes such as porous nanotubes, porous nanospheres and so on have been investigated, that not only possessed large surface area and relatively mass reactive sites, but also formed relatively loose film structures which is an advantage for gas diffusion Besides, doping is also an effective method to decrease particle size and improve gas sensing properties Therefore, the gas sensing properties of metal oxide nanostructures assembled by nanoparticles are reviewed in this article The effect of doping is also summarized and finally the perspectives of metal oxide gas sensor are given

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Metal Oxide Nanostructures and Their Gas Sensing Properties: A Review

Aligned Single‐Crystalline Si Nanowire Arrays for Photovoltaic Applications

Mobility improvement of LTPS thin film transistor using stacked capping layer

A Brief Review on Variables and Test Priorities of Photovoltaic Module Life Expectancy

We report the effect of thin-film transistors (TFTs) without an active pattern (TFTs w/o an active pattern) on the improvement of the drain current and on the reduction of the drain-induced barrier lowering (DIBL) effect. The electrical characteristics of TFTs w/o an active pattern are immensely different from those of normal TFTs because they are composed of a channel area with wholly preserved excimer laser annealing processed poly-silicon (poly-Si) and a specially designed gate electrode. An un-etched poly-Si layer can be utilized as a channel region by designing the gate metal. The extended electric field following the shape of the gate electrode increases the drain current by six to seven times compared to that of normal TFTs. Furthermore, the extended channel area can reduce the DIBL effect considerably. Since the un-etched poly-Si layer has no sharp slope angles or tips on the edge of the precursor, TFTs w/o an active pattern are highly resistant to breakdowns of the gate insulator. Finally, the reducing photo-lithography process on the precursor layers of TFTs effectively simplifies back-plane fabrication.

http://iopscience.iop.org/article/10.1088/0268-1242/28/10/105018/pdf

Poly-silicon thin-film transistors without active layer pattern for high current performance with large operational range

We employed a novel inorganic-organic hybrid triple junction solar cell (IOHTC), with an inorganic silicon tandem cell (ITC) that is series connected to an organic solar cell (OSC) at the back of the ITC. The ITC is used to absorb the short wavelength part of the solar spectrum, while the organic bottom cell utilizes the long wavelength part of the spectrum. The IOHTC was fabricated with hydrogenated amorphous silicon (a-Si:H) and PTB7:PCBM as active layers. The optical gap (Eg) of the active layers of the front to the back cells was 1.83 eV, 1.80 eV and 1.55 eV, respectively. The efficiency of the optimized IOHTC reached a maximum of 7.70% with high open circuit voltage (V oc ) 2.33 V. The observed V oc of the IOHTC was 96.31% of the sum of the V oc of the individual component cells. In one of the IOHTC, the total current density (J sc ) increased by 11.19% and 14.13% as compared with total J sc of the OSC and ITC, respectively.

Junsin Yi

Papers

Mobility improvement of LTPS thin film transistor using stacked capping layer

A Brief Review on Variables and Test Priorities of Photovoltaic Module Life Expectancy

Poly-silicon thin-film transistors without active layer pattern for high current performance with large operational range

Advanced triple junction solar cell by employing inorganic-organic hybrid materials

Current Status in Light trapping Technique for Thin Film Silicon Solar Cells