• 전기학회논문지
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• 제65권10호
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• pp.1702-1705
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• 2016

We propose a novel hydrogen-reduced p-type amorphous silicon oxide buffer layer between $TiO_2$ antireflection layer and p-type silicon window layer of silicon thin film solar cells. This new buffer layer can protect underlying the $TiO_2$ by suppressing hydrogen plasma, which could be made by excluding $H_2$ gas introduction during plasma deposition. Amorphous silicon oxide thin film solar cells with employing the new buffer layer exhibited better conversion efficiency (8.10 %) compared with the standard cell (7.88 %) without the buffer layer. This new buffer layer can be processed in the same p-chamber with in-situ mode before depositing main p-type amorphous silicon oxide window layer. Comparing with state-of-the-art buffer layer of AZO/p-nc-SiOx:H, our new buffer layer can be processed with cost-effective, much simple process based on similar device performances.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.336-340
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• 2012

Wide band gap p-type hydrogenated amorphous silicon oxide (a-SiO:H) buffer layer has been used at the interface of transparent conductive oxide (TCO) and hydrogenated amorphous silicon (a-Si:H) p-type layer of a p-i-n type a-Si:H solar cell. Introduction of 5 nm thick buffer layer improves in blue response of the cell along with 0.5% enhancement of photovoltaic conversion efficiency (η). The cells with buffer layer show higher open circuit voltage (Voc), fill factor (FF), short circuit current density (Jsc) and improved blue response with respect to the cell without buffer layer.

• 한국세라믹학회지
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• 제52권4호
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• pp.290-293
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• 2015

The properties of the IZTO thin films on the glass were studied with a variation of the $SiO_2$ buffer layer thickness. $SiO_2$ buffer layers were deposited by plasma-enhanced chemical vapor deposition (PECVD) on the glass, and the In-Zn-Tin-Oxide (IZTO) thin films were deposited on the buffer layer by RF magnetron sputtering. All the IZTO thin films with the $SiO_2$ buffer layer are shown to be amorphous. Optimum $SiO_2$ buffer layer thickness was obtained through analyzing the structural, morphological, electrical, and optical properties of the IZTO thin films. As a result, the IZTO surface roughness is 0.273 nm with a sheet resistance of $25.32{\Omega}/sq$ and the average transmittance is 82.51% in the visible region, at a $SiO_2$ buffer layer thickness of 40 nm. The result indicates that the uniformity of surface and the properties of the IZTO thin film on the glass were improved by employing the $SiO_2$ buffer layer and the IZTO thin film can be applied well to the transparent conductive oxide for display devices.

• 한국재료학회지
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• 제21권1호
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• pp.34-38
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• 2011

In this study, the effects of an annealed buffer layer with different thickness on heterojunction diodes based on the ZnO/ZnO/p-Si(111) systems were reported. The effects of an annealed buffer layer with different thickness on the structural, optical, and electrical properties of zinc oxide (ZnO) films on p-Si(111) were also studied. Before zinc oxide (ZnO) deposition, different thicknesses of ZnO buffer layer, 10 nm, 30 nm, 50 nm and 70 nm, were grown on p-Si(111) substrates using a radio-frequency sputtering system; samples were subsequently annealed at $700^{\circ}C$ for 10 minutes in $N_2$ in a horizontal thermal furnace. Zinc oxide (ZnO) films with a width of 280nm were also deposited using a radio-frequency sputtering system on the annealed ZnO/p-Si (111) substrates at room temperature; samples were subsequently annealed at $700^{\circ}C$ for 30 minutes in $N_2$. In this experiment, the structural and optical properties of ZnO thin films were studied by XRD (X-ray diffraction), and room temperature PL (photoluminescence) measurements, respectively. Current-voltage (I-V) characteristics were measured with a semiconductor parameter analyzer. The thermal tensile stress was found to decrease with increasing buffer layer thickness. Among the ZnO/ZnO/p-Si(111) diodes fabricated in this study, the sample that was formed with the condition of a 50 nm thick ZnO buffer layer showed a strong c-axis preferred orientation and I-V characteristics suitable for a heterojunction diode.

• 한국전기전자재료학회논문지
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• 제30권8호
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• pp.491-495
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• 2017

We investigated solution-processed indium-zinc oxide (IZO) thin-film transistors (TFTs) by inserting a 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) buffer layer. This buffer layer efficiently tuned the energy level between the semiconducting oxide channel and metal electrode by increasing charge extraction, thereby enhancing the overall device performance: the IZO TFT with embedded PBD layer (thickness: 5 nm; width: $2,000{\mu}m$; length: $200{\mu}m$) exhibited a field-effect mobility of $1.31cm^2V^{-1}s^{-1}$, threshold voltage of 0.12 V, subthreshold swing of $0.87V\;decade^{-1}$, and on/off current ratio of $9.28{\times}10^5$.

• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.102-105
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• 2011

This work describes the characteristics of zinc oxide (ZnO) thin films formed on a polycrystalline (poly) 3C-SiC buffer layer using a sol-gel process. The deposited ZnO films were characterized using X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectra. ZnO thin films grown on the poly 3C-SiC buffer layer had a nanoparticle structure and porous film. The effects of post-annealing on ZnO film were also studied. The PL spectra at room temperature confirmed the crystal quality and optical properties of ZnO thin films formed on the 3C-SiC buffer layer were improved due to close lattice mismatch in the ZnO/3C-SiC interface.

• 한국전기전자재료학회논문지
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• 제23권1호
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• pp.24-28
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• 2010

We have proposed an Buffer layer to improve the transmittance of ITO. Here, $SiO_2$ and $TiO_2$ were selected as the Buffer layer coating material. The structures of Buffer layer were designed in ITO/$SiO_2/TiO_2$/Glass and ITO/Glass/$TiO_2/SiO_2$. Then, these materials were deposited by ion-assisted deposition system. Transmittances of deposited ITO were 86.14 and 85.07%, respectively. These results show that the proposed structure has higher transmittance than the conventional ITO device.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.206-206
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• 2011

투명 전도성 산화물 (TCO, Transparent Conductive Oxide) 박막을 태양전지에 적용하기 위해서는 우수한 전기 전도성 및 가시광 영역에서 높은 투과율을 가져야 한다. 대표적인 TCO 물질인 ITO (Indium tin oxide) 박막은 우수한 전기적, 광학적 특성을 가지고 있지만 $400^{\circ}C$ 이상의 고온에서는 전기저항이 급격히 증가하게 되어 실제 태양전지 패널에 적용했을 때 전기적 특성이 저하된다. 따라서 태양전지용 TCO 박막을 개발 시, 뛰어난 고온 안정성이 요구되고 있다. 본 연구에서는 고온 안정적 특성을 지니는 Ga3+를 도핑한 ZnO 계열 TCO인 GZO/ITO multi-layered 박막을 증착하였다. 또한 buffer layer의 두께 변화 및 구조 제어를 통한 최위층 박막의 전기적 특성 및 결정성을 조사하였으며 다층 박막의 계면 간 특성 및 굴절률 제어를 통한 광학적 물성을 연구하였다.

• 한국세라믹학회지
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• 제52권1호
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• pp.72-76
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• 2015

150-nm-thick In-Zn-Tin-Oxide (IZTO) films were deposited by RF magnetron sputtering after a 10 to 50-nm-thick $SiO_2$ buffer layer was deposited by plasma enhanced chemical vapor deposition (PECVD) on polyethylene terephthalate (PET) substrates. The electrical, structural, and optical properties of the IZTO/$SiO_2$/PET films were analyzed with respect to the thickness of the $SiO_2$ buffer layer. The mechanical properties were outstanding at a $SiO_2$ thickness of 50 nm, with a resistivity of $1.45{\times}10^{-3}{\Omega}-cm$, carrier concentration of $8.84{\times}10^{20}/cm^3$, hall mobility of $4.88cm^2/Vs$, and average IZTO surface roughness of 12.64 nm. Also, the transmittances were higher than 80%, and the structure of the IZTO films were amorphous, regardless of the $SiO_2$ thickness. These results indicate that these films are suitable for use as a transparent conductive oxide for transparency display devices.

• 한국재료학회지
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• 제17권2호
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• pp.61-67
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• 2007

The magnetron reactive sputtering was adopted to deposit CuO buffer layers on the polyimide surfaces for increasing the adhesion strength between Cu thin films and polyimide, varying $O_2$ gas flow rate from 1 to 5 sccm. The CuO oxide was formed through all the $O_2$ gas flow rates of 1 to 5 sccm, showing the highest value at the 3 sccm $O_2$ gas flow rate. The XPS analysis revealed that the $Cu_2O$ oxide was also formed with a significant ratio during the reactive sputtering. The adhesion strength is mainly dependent on the amount of CuO in the buffer layers, which can react with C-O-C or C-N bonds on the polyimide surfaces. The adhesion strength of the multi-layered Cu/buffer layer/polyimide specimen decreased linearly as the heating temperature increased to $300^{\circ}C$, even though there showd no significant change in the chemical state at the polyimide interface. This result is attributed to the decrease in surface roughness of deposited copper oxide on the polyimide, when it is heated.