• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.388-388
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• 2011

본 연구에서는 CuO 나노 입자를 poly(3,4,-ethylene dioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) 버퍼층에 첨가하여 정공의 이동도를 높임으로서 poly(3-hexylthiophene) (P3HT) as the electron donor and (6.6) phenyl-C61-butyric acid methyl ester (PCBM) 기반의 유기 태양전지를 제작하였다. 일반적으로 PEDOT:PSS 박막은 높은 광 투과율과 상대적으로 우수한 전기전도도를 지닌 p-type의 유기 반도체 물질로써 유기 태양전지의 홀 전도막으로 널리 사용되어지고 있다. 하지만 낮은 홀이동도로 인하여 전달된 정공이 전극까지 전달되는데에 한계점이 있어 본 연구에서 이를 극복하기 위한 방안으로 p-type의 무기 반도체 물질인 CuO 나노 입자를 PEDOT:PSS 박막내에 첨가하여 홀 이동도를 높이고자 하였다. CuO 나노 입자를 PEDOT:PSS 용액에 각각 5, 10, 15, 20mg/ml 의 농도로 첨가하여 유기 태양 전지의 버퍼층으로 사용을 하였다. 이렇게 제작되어진 각각의 PEDOT:PSS 박막과 CuO 나노 입자가 첨가된 PEDOT:PSS 박막의 전기적, 광학적 및 표면 분석을 통하여 CuO 나노 입자가 PEODT:PSS 박막에 미치는 영향을 조사하였고, 이를 통하여 P3HT:PCBM 기반의 유기 태양전지를 제작하여 전기적 특성 분석을 수행하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.321-321
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• 2010

The PEDOT:PSS layer is usually used as hole transporting layer for the polymer bulk heterojunction solar cells. However, the interface between ITO and PEDOT:PSS is not stable and the chemical reaction between ITO and PEDOT can result in degraded device performance. We used the tungsten oxides as a hole transport layer by spin-coating. The $WO_3$ nanoparticles were well dispersed in ammonium hydroxide and deionized water and formed thin layer on the ITO anode. We found that $WO_3$ surface is more hydrophobic than the bare ITO or PEDOT:PSS-coated surfaces. The hydrophobic surfaces promote an ordered growth of P3HT films. A higher degree of P3HT ordering is expected to improve the hole mobility and the lifetime of the device using the tungsten oxide showed better stability compared to the device using the PEDOT:PSS.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.88-93
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• 2008

The bulk-heterojunction polymer solar cell based on regioregular P3HT (poly(3-hexylthiophene)) and PCBM (methanofullerene [6,6]-phenyl $C_{61}$-butyric acid methyl ester) was fabricated. Annealing effects on the crystal structure of polymer-fullerene blends as well as the UV-VIS electronic absorption spectroscopy were investigated. The correlation between the crystal organization of bulk-heterojunction film and the power conversion efficiency of solar cell was studied. Resultantly, the polymer solar cell annealed on $150^{\circ}C$ for 30 min, showed both the enhanced molecular interactions and the optimized crystal structure and displayed the power conversion efficiency of 3.2 %.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.252-256
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• 2013

We introduced sensitizing dyes into the bulk-heterojunction (BHJ) photovoltaic (PV) layer of polymer solar cells (PSCs). The sensitizing dyes doped were Bis(tetra butyl ammonium) cis-dithio cyanato bis(2,2'-bipyridine-4-carboxylicacid-4'-carboxylate) ruthenium (II) (N719 dye) and the BHJ PV layer used was made of poly (3-hexylthiophene) (P3HT) and phenyl $C_{61}$-butyric acid methyl ester (PCBM). It was found that the N719 dyes increase the photovoltaic performance, i.e., increasing open-circuit voltage and short-circuit current density with improved fill factor. For the P3HT:PCBM PV cells doped with the N719 dyes (0.24 wt%), an increase in power conversion efficiency of 4.0% was achieved, compared to that of the control cells (3.6%) without the N719 dyes.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.69.2-69.2
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• 2010

Recently, bulk hetero-junction cells have been extensively studied by many researchers. Most of these cells were fabricated by spin coater. However, the spin coating process is not favorable to the large-scaled industry because it is not compatible with roll-to-roll process. One of the alternative methods is Doctor blading. In this study, we fabricated large OPV cells having total area of $100cm^2$. The buffer layer was Poly-(3,4-ethylenedioxythiophene) : poly-(styrenesulfonate) aqueous dispersion (PEDOT:PSS) and the active material is poly (3-hexythiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend in the solvent of Chlorobenzene. All of the organic layers were coated by dragging the blade with a speed of 5~20 mm/s on the stage with a temperature of $50^{\circ}C$. As-bladed PEDOT:PSS layer was baked at $120^{\circ}C$ for 10 minutes to eliminate the water. The cell structure is patterned ITO substrate/PEDOT:PSS/P3HT:PCBM/LiF/Al. The topmost electrode, LiF/Al, was deposited by thermal evaporation. After depositing electrode, and the cell was annealed at $150^{\circ}C$ for 30 minutes. The measured ISC, VOC, fill factor, and PCE were 2.95 A, 5.86 V, 0.32, and 0.78%, respectively. PCE was quite low but the large active area could be obtained successfully.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.57.1-57.1
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• 2011

We studied the performance of CdSe nanoparticle in the active layer of organic photovoltaics (OPVs) by changing concentration of the CdSe NPs in the P3HT:PCBM layer. We observed that the absorption peak value gradually increases with the increasing amount of CdSe NPs at 600nm wave length. However, the electrical properties of OPVs correspond less with the tendency of UV/visible result. The highest performance was shown with 10% of CdSe NPs. The device performance decreased after 10% of CdSe NPs, this shows the dependencies of performanc of hybrid solar cells on the CdSe NPs loading amount. The resulting OPVs with 10 % of CdSe NPs show a short circuit current density ($J_{sc}$) of $6.96mA/cm^2$, open circuit voltage ($V_{oc}$) of 0.61V, fill factor (FF) of 0.59, and power conversion efficiency (PCE) of 2.53% under AM 1.5 ($100mW/cm^2$).

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.267-267
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• 2009

• Advances in Energy Research
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• v.4 no.4
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• pp.275-284
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• 2016

In the present work, ZnO nanoparticles (NPs) have been dispersed alone in the same solvent of the active layer for improving performance parameters of the organic solar cells. Different concentrations of the ZnO NPs have been blended inside active layer of the solar cell based on poly(3-hexylthiophene) (P3HT), which forms the hole-transport network, and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which forms the electron-transport network. In the present investigations, the ZnO NPs may represent an efficient tool for improving light harvesting through light scattering inside active layer, electron mobility, and electron acceptance strength which tend to improve photocurrent and performance parameters of the investigated solar cell. The fill factor (FF) of the ZnO-doped solar cell increases nearly 14% compared to the non-doped solar cell when the doping is 50%. The present investigations show that ZnO NPs improve power conversion efficiency of the solar cell from 1.23% to 1.64% with increment around 25% that takes place after incorporation of 40% as a volume ratio of the ZnO NPs inside P3HT:PCBM active layer.

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

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.457-458
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• 2008

본 연구에서는 PCBM([6，6]-Phenyl $C_{61}$ butric acid methyl ester)과 P3HT(Poly(3-hexylthiophene-2,5-diyl (regiorandom))의 Donor, Acceptor 물질을 이용하여 스핀코팅법을 사용하여 PEDOT가 코팅된 ITO 유리기판에 스핀 코팅법을 사용하여 광활성층을 증착하였다. 이렇게 코팅된 유리기판에 열 증착법 사용하여 Al(cathode층)전극을 증착하여 유기태양전지를 제작하였다. 각각의 층에 대해서 SEM(전자주사현미경)을 이용하여 두께를 측정하였고 UV분광계를 이용하여 투과도를 측정하고 투과도를 이용하여 광학적 밴드갭을 계산하였다. ITO/PEDOT/ACTIVE AREA/Al 구조의 태양전지를 제작하여 광활성층의 두께와 Al의 두께에 따른 효율성을 측정하여 1% 이내의 효율을 보이는 태양전지를 제작하였다. PEDOT는 OLED에서 HTL층으로 사용되며 흘의 이동을 원활하게 해주는 역할을 한다.