• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.385-385
• /
• 2011

Si 또는 반도체 화합물을 기반으로 한 태양전지의 높은 원재료 가격과 복잡한 공정 등의 문제점들을 해결하기 위한 방안으로 반도체성 고분자인 Poly(3-hexylthiophene)(P3HT)과 C60 유도체인 PCBM을 광활성 층으로 이용하여 유기 태양전지(Organic Solar Cell, OSC)를 제작하였다. 하지만 상대적으로 낮은 효율을 갖는 OSC의 단점을 해결하기 위해서 유기물 자체가 갖고 있는 광 안정성, 낮은 전하 이동도 및 광 에너지 흡수대 등의 문제점들의 해결 방안들이 제시되고 있다. 본 연구에서는 광활성 층을 사용한 유기 태양전지의 특성에서 후열처리에 따른 유기 태양전지의 전기적 및 구조적, 광학적인 특성들이 소자의 효율에 끼치는 영향에 대해 분석하였다. 후열 처리 온도에 따른 광활성 층의 구조적인 특성을 분석하기 위해 EFM 이미지와 XRD패턴을 측정하였는데 열처리 후 박막의 전기적인 포텐셜과 결정성 향상의 유기 태양전지의 효율향상에 기여함을 알 수 있었다. 또한 임피던스 분석 장치를 이용해 후열 처리에 따른 소자의 Resistance, Capacitance, I-V 곡선들을 분석한 결과 최적의 조건에서 열처리된 광활성 층은 전하들의 이동을 조절하여 소자 내에서 Capacitance를 증가시키는 것 뿐만 아니라 전극과 유기물 층 사이의 계면 특성을 향상시킴으로써, 소자의 효율을 증가시키는 원인으로 작용함을 확인 하였다.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.236-246
• /
• 2004

Artificial carious lesions in various depths were observed with visual examination using light transillumination, bite-wing radiography, laser fluorescence, and dye-enhanced laser fluorescence to determine the reproducibility, correlation of each diagnostic method, diagnostic sensitivity and diagnostic specificity. And optical densities according to demineralized times were measured whether laser fluorescence could be used as a quantitative diagnostic method. The following results were obtained whether laser fluorescence could be used for diagnosis of initial proximal caries. 1. Tau-c values of visual examination was 0.08 which showed lowest reproducibility and those of bite-wing radiography, laser fluorescence, dye-enhanced laser fluorescence were 0.60, 0.48, and 0.64, respectively which showed relatively high reproducibility. 2. The correlation between demineralization time and each examination was the highest in dye-enhanced laser fluorescence$({\gamma}=0.51)$ followed by laser fluorescence$({\gamma}=0.43)$, bite-wing radiograph$({\gamma}=0.35)$, and visual examination$({\gamma}=0.33)$. Dye-enhanced laser fluorescence and laser fluorescence showed significant correlation with demineralization time. 3. The sensitivity of laser fluorescence and dye-enhanced laser fluorescence for diagnosing approximal caries based on bite-wing radiography were 67%, 100% and those of specificity were 57%, 11% which showed diagnostic specificity was relatively lower than sensitivity. 4. The difference in optical density(DFR) between sound teeth and carious lesions according to lesion depth was high with dye-enhanced laser fluorescence compared with laser fluorescence. DFR measured with laser fluorescence according to changes in lesion depth was statistically significant but was not statistically significant with dye-enhanced laser fluorescence. Based on these results, laser fluorescence and dye-enhanced laser fluorescence have comparable diagnostic power as bite-wing radiography in early diagnosis of proximal caries.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.05b
• /
• pp.401-402
• /
• 2003

TiO$_2$는 광촉매로서 자외선이 조사되면 여기상태로 되어 광활성을 나타내므로, 휘발성 유기화합물(VOCs), 악취, 중금속 물질 등을 제어하는데 널리 사용되고 있다(Lee and Biswas, 1998). TiO$_2$는 기상 및 액상 등 여러 가지 방법으로 제조되고 있는데(Morooka et al., 1989), 본 연구에서는 기상 방법의 하나인 전기가열 튜브로를 이용하여 TiOs 입자를 제조하였다. 즉, TTIP(titanium isopropoxide, Ti[OCH($CH_3$)$_2$]$_4$)와 공기를 전기가열 튜브로의 d열원을 이용하여 반응시키는 방법을 사용하였다. TiO2의 광활성에 영향을 미치는 변수로는 전기로의 온도, TTIP의 초기 농도, carrier gas의 유량, 산화시키기 위한 산소의 양, 수분의 양 등이 있다. (중략)

• Proceedings of the Optical Society of Korea Conference
• /
• 1991.06a
• /
• pp.172-176
• /
• 1991

4d 전이원소인 rhodium을 phosphate 유리에 첨가하여 광흡수 및 photoluminescence 스펙트럼을 측정하였다. 이로써 rhodium 이온의 tunable solid state laser용의 광활성 이온으로서의 가능성을 조사하였다.

• The Korean Journal of Pesticide Science
• /
• v.11 no.1
• /
• pp.38-45
• /
• 2007

Laboratory and greenhouse experiments were conducted to determine the herbicidal effect of two types of ${\delta}$-aminolevulinic acid (ALA), microbiologically-produced ALA (Bio-ALA) and synthetically produced ALA (Synthetic-ALA), on plant growth and chlorophyll content of Chinese cabbage. ALA effect on early plant growth was greatly concentration dependant, showing significant inhibition at higher concentrations. Both pre- and post-emergence application of ALA exhibited significant degree of photodynamic phytotoxicity. Older plants with many leaves were more tolerant to ALA than younger plants, showing less injury. No significant difference in herbicidal activity of two types of ALA, Bio-ALA and Synthetic-ALA, on plant height and chlorophyll content of Chinese cabbage was observed. However, residual biological activity and physico-chemical properties of Synthetic-ALA were more stable than those of Bio-ALA. Our results suggest that ALA had herbicidal potential with both pre- and post-emergence application, and that the chemical may be a valuable mean of eco-friendly weed control based on natural microbial substance.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2007.05a
• /
• pp.509-510
• /
• 2007

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.247-248
• /
• 2006

• Proceedings of the Optical Society of Korea Conference
• /
• 2007.07a
• /
• pp.163-164
• /
• 2007

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.02a
• /
• pp.171-172
• /
• 2008

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.02a
• /
• pp.173-174
• /
• 2008