• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.400-400
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• 2009

Despite the success of Cu(In,Ga)$Se_2$ (CIGS) based PV technology now emerging in several industrial initiatives, concerns about the cost of In and Ga are often expressed. It is believed that the cost of those elements will eventually limit the cost reduction of this technology. One candidate to replace CIGS is $Cu_2ZnSnSe_4$ (CZTSe), fabricated by co-evaporation technique. Co-evaporation technique will be one of the best methods to control film composition. This type of absorber derives from the $CuInSe^2$ chalcopyrite structure by substituting half of the indium atoms with zinc and other half with tin. Energy bandgap of this material has been reported to range from 0.8eV for selenide to 1.5eV for the sulfide and large coefficient in the order of $10^{14}cm^{-1}$, which means large possibility of commercial production of the most suitable absorber by using the CZTSe film. In this work, Effects of substrate temperature of $Cu_2ZnSnSe_4$ absorber layer on the performance of thin films solar cells were investigated. We reported on some of the absorber properties and device results.

• Safety and Health at Work
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• v.3 no.4
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• pp.257-267
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• 2012

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

• Current Photovoltaic Research
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• v.10 no.2
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• pp.33-38
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• 2022

Planner configuration thin film solar cells (TFSCs) with SnS/CdS heterojunction performed a lower short-circuit current (J_SC). In this study, we have demonstrated a path to overcome deficiency in J_SC by the incorporation of Se in the SnS absorber. We carried out the incorporation of Se in VTD grown SnS absorber by rapid thermal annealing (RTA). The diffusion of Se is mostly governed by RTA temperature (T_RTA), also it is observed that film structure changes from cube-like to plate-like structure with T_RTA. The maximum J_SC of 23.1 mA cm^-2 was observed for 400℃ with an open-circuit voltage (V_OC) of 0.140 V for the same temperature. The highest performance of 2.21% with J_SC of 18.6 mA cm^-2, V_OC of 0.290 V, and fill factor (FF) of 40.9% is observed for a T_RTA of 300℃. In the end, we compare the device performance of Se- incorporated SnS absorber with pristine SnS absorber material, increment in J_SC is approximately 80% while a loss in V_OC of about 20% has been observed.

• Journal of Aquaculture
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• v.4 no.2
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• pp.111-128
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• 1991

In puan area the environmental surveys were carried out at two farms of hard clam, Meretrix lusoria from April 1987 to November 1978 in order to know heather the farm environments could be rehabilitated for the cultivation of hard clam or not. The range of temperature of surface seawater was $10.7{\~}27.4^{\circ}C$, pH $7.6{\~}8.2$, salinity $22.3{\~}30.3$ ppt, COD $0.20{\~}4.71\;mg/{\ell}$, sulfide $0.04{\~}0.22\;{\mu}g-at./{\ell}$, suspended solid $34.8{\~}199.3\;mg/{\ell}$ chlorophyll a $3.71{\~}49.02\;mg/m^3$, TIN $2.01{\~}24.47\;{\mu}g-a5./{\ell}$, phosphate $0.60{\~}11.03\;{\mu}g-at./{\ell}$ and silicate $4.04{\~}476.36\;{\mu}g-at./{\ell}$. The range of temperature of substratum (bottom soil) was $14.2{\~}29.7^{\circ}C$, pH $8.3{\~}9.5$, water content of substratum was $0.28{\~}0.49\;mg/g$ dried mud, COD $2.80{\~}50.94\;mg/g$ dried mud, total organic matter $1.05{\~}1.97\%$ concentration of total Kjedhal nitrogen $31.9{\~}194.9\;{\mu}g./{\ell}$ dried mud, and sulfide $0.032{\~}0.133\;mg/g$ dried mud. Fine sand was dominant ranging over $92{\~}95\%$ and silt and clay was $2.8{\~}8.1\%$ of the composition of substratum. Some residual agricultural chemicals, ${\alpha},\;{\beta},\;{\gamma}$-BHC, heptachlor, heptachlor-epoxide, aldrin, DDE, DDT and dieldrin were detected in hard clams collected from Puan areas. Especialy, more chemical were detected during the period of rainfalls. From above results, it is considered that the hard clam frams were not yet recovered from deteriorated conditions for aquaculture.

• Economic and Environmental Geology
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• v.19 no.2
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• pp.109-122
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• 1986

Mn-Pb-Zn-Ag deposits of the Janggun mine are hosted in the Cambro-Ordovician Janggun limestone mostly along the contacts of the Jurassic Chunyang granite. The deposits are represented by several ore pipes and steeply dipping lenticular bodies consisting of lower Pb-Zn-Ag sulfide ores and upper manganese carbonate and oxide ores. The former consists mainly of arsenic, antimony, silver, manganese, and tin-bearing sulfides, whereas the latter are characterized by hypogene rhodochrosite, and superficial manganese oxides including todorokite, nsutite, pyrolusite, cryptomelane, birnesite and janggunite. Origin of the upper manganese ore deposits has been a controversial subject among geologists for this mine: hydrothermal metasomatic vs. syngenetic sedimentary origin. Syngenetic advocators have proposed a new sedimentary rock, rhodochrostone, which is composed mainly of rhodochrosite in mineralogy. In the present study, carbon, oxygen and sulfur isotopic compositions were analayzed obtaining results as follows: Rhodochrosite minerals, (Mn, Ca, Mg, Fe) $CO_3$, from hydrothermal veins, massive sulfide ores and replacement ores in dolomitic limestone range in isotopic value from -4.2 to -6.3‰ in ${\delta}^{13}C$(PDB) and +7.6 to +12.9‰ in ${\delta}^{18}O$(SMOW) with a mean value of -5.3‰ in ${\delta}^{13}C$ and +10.7‰ in ${\delta}^{18}O$. The rhodochrosite bearing limestone and dolomitic limestone show average isotopic values of -1.5‰ in ${\delta}^{13}C$ and +17.5‰ in ${\delta}^{18}O$, which differ from those of the rhodochrosite mentioned above. This implies that the carbon and oxygen in ore fluids and host limestone were not derived from an identical source. ${\delta}^{34}S$ values of sulfide minerals exhibit a narrow range, +2.0 to +5.0‰ and isotopic temperature appeared to be about $288{\sim}343^{\circ}C$. Calculated initial isotopic values of rhodochrosite minerals, ${\delta}^{18}O_{H_2O}=+6.6$ to +10.6‰ and ${\delta}^{13}C_{CO_2}=-4.0$ to -5.1 ‰, strongly suggest that carbonate waters should be deep seated in origin. Isotopic data of manganese oxide ores derived from hypogene rhodochrosites suggest that the oxygen of the limestone host rock rather than those of meteoric waters contribute to form manganese oxide ores above the water table.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.65-65
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• 2012

Copper zinc tin sulfide ($Cu_2ZnSnS_4$, CZTS) is a very promising material as a low cost absorber alternative to other chalcopyrite-type semiconductors based on Ga or In because of the abundant and economical elements. In addition, CZTS has a band-gap energy of 1.4~1.5eV and large absorption coefficient over ${\sim}10^4cm^{-1}$, which is similar to those of $Cu(In,Ga)Se_2$(CIGS) regarded as one of the most successful absorber materials for high efficient solar cell. Most previous works on the fabrication of CZTS thin films were based on the vacuum deposition such as thermal evaporation and RF magnetron sputtering. Although the vacuum deposition has been widely adopted, it is quite expensive and complicated. In this regard, the solution processes such as sol-gel method, nanocrystal dispersion and hybrid slurry method have been developed for easy and cost-effective fabrication of CZTS film. Among these methods, the hybrid slurry method is favorable to make high crystalline and dense absorber layer. However, this method has the demerit using the toxic and explosive hydrazine solvent, which has severe limitation for common use. With these considerations, it is highly desirable to develop a robust, easily scalable and relatively safe solution-based process for the fabrication of a high quality CZTS absorber layer. Here, we demonstrate the fabrication of a high quality CZTS absorber layer with a thickness of 1.5~2.0 ${\mu}m$ and micrometer-scaled grains using two different non-vacuum approaches. The first solution-processing approach includes air-stable non-toxic solvent-based inks in which the commercially available precursor nanoparticles are dispersed in ethanol. Our readily achievable air-stable precursor ink, without the involvement of complex particle synthesis, high toxic solvents, or organic additives, facilitates a convenient method to fabricate a high quality CZTS absorber layer with uniform surface composition and across the film depth when annealed at $530^{\circ}C$. The conversion efficiency and fill factor for the non-toxic ink based solar cells are 5.14% and 52.8%, respectively. The other method is based on the nanocrystal dispersions that are a key ingredient in the deposition of thermally annealed absorber layers. We report a facile synthetic method to produce phase-pure CZTS nanocrystals capped with less toxic and more easily removable ligands. The resulting CZTS nanoparticle dispersion enables us to fabricate uniform, crack-free absorber layer onto Mo-coated soda-lime glass at $500^{\circ}C$, which exhibits a robust and reproducible photovoltaic response. Our simple and less-toxic approach for the fabrication of CZTS layer, reported here, will be the first step in realizing the low-cost solution-processed CZTS solar cell with high efficiency.

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.40-47
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• 2024

The creation of vertically aligned one-dimensional (1D) nanostructures through the decoration of n-type tin oxide (SnO₂) on p-type chromium oxide (Cr₂O₃) constitutes an effective strategy for enhancing gas sensing performance. These heterostructures are deposited in multiple stages using a glancing angle deposition technique with an electron beam evaporator, resulting in a reduction in the surface porosity of the nanorods as SnO₂ is incorporated. In comparison to Cr₂O₃ films, the bare Cr₂O₃ nanorods exhibits a response 3.3 times greater to 50 ppm H₂S at 300℃, while the SnO₂-decorated Cr₂O₃ nanorods demonstrate an eleven-fold increase in response. Furthermore, when subjected to various gases (CH₄, H₂S, CO₂, H₂), a notable selectivity toward H₂S is observed. This study paves the way for the development of p-type semiconductor sensors with heightened selectivity and sensitivity towards H₂S, thus advancing the prospects of gas sensor technology.