• Current Photovoltaic Research
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• v.3 no.2
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• pp.54-60
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• 2015

ZnSnO thin films were deposited by atomic layer deposition (ALD) process using diethyl zinc ($Zn(C_2H_5)_2$) and tetrakis (dimethylamino) tin ($Sn(C_2H_6N)_4$) as metal precursors and water vapor as a reactant. ALD process has several advantages over other deposition methods such as precise thickness control, good conformality, and good uniformity for large area. The composition of ZnSnO thin films was controlled by varying the ratio of ZnO and $SnO_2$ ALD cycles. The ALD ZnSnO film was an amorphous state. The band gap of ZnSnO thin films increased as the Sn content increased. The CIGS solar cell using ZnSnO buffer layer showed about 18% energy conversion efficiency. With such a high efficiency with the ALD ZnSnO buffer and no light soaking effect, AlD ZnSnO buffer mighty be a good candidate to replace Zn(S,O) buffer in CIGSsolar cells.

• 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.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.314-320
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• 2002

Three different ZnO nanomaterials (nanobelts, nanorods, and nanowires) were synthesized at 138$0^{\circ}C$ from ball-milled ZnO powders by a thermal evaporation procedure with an argon carrier gas without any catalysts. Transmission electron microscopy (TEM) revealed that the ZnO nanobelts are single crystalline with the growth direction perpendicular to the (010) lattice plane, and that the ZnO nanorods and nanowires are single crystalline with the growth directions perpendicular to the (001) and (110) lattice Planes, respectively. In cathodoluminescence (CL), the energy Position of the near band-edge (NBE) peak is 3.280 eV for the 100-, 250-, and 500-nm thick nanobelts, 3.262 eV for the 100- and 250-nm thick nanorods, and 3.237 eV for the 500-nm thick nanorods. The synthesized ZnO nanorods were coated conformally with aluminum oxide (Al$_2$O$_3$) material by atomic layer deposition (ALD). $Al_2$O$_3$films were then deposited on these ZnO nanorods by ALD at a substrate temperature of 300 $^{\circ}C$ using trimethylaluminum (TMA) and distilled water ($H_2O$). Transmission electron microscopy (TEM) images of the deposited ZnO nanorods revealed that 40nm-thick $Al_2$O$_3$ cylindrical shells surround the ZnO nanorods.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.79-81
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• 2002

ZnO 나노와이어는 ZnO 파우더를 볼밀 처리하여 열증착 방법으로 $1380^{\circ}C$에서 촉매없이 Si 기판위에서 합성되었다. 합성된 ZnO 나노와이어의 길이와 직경은 $20{\sim}30{\mu}m$와 $50{\sim}200$ nm 였다. ZnO 나노와이어 표면을 atomic layer deposition(ALD) 방법으로 $Al_2O_3$ 박막을 얇게 코팅하였다. 성장온도는 $300^{\circ}C$였고, 사용한 전구체는 Trimethlaluminum(TMA)와 distilled water($H_2O$) 이다. Transmission electron microscopy(TEM) 으로 측정한 $Al_2O_3$ 박막의 두께는 40 nm 로서 매우 균일하게 ZnO 나노와이어에 증착되었음을 알 수 있었다.

• Current Photovoltaic Research
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• v.5 no.4
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• pp.135-139
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• 2017

We fabricated two different transparent conducting oxide thin films of ZnO doped with Ga ($Ga_2O_3$ 0.9 wt%) as well as Al ($Al_2O_3$ 2.1 wt%) (GAZO) and ZnO doped only with Al ($Al_2O_3$ 3 wt%) (AZO). It was investigated how it affects the moisture resistance of the transparent electrode. In addition, $Cu(In,Ga)Se_2$ thin film solar cells with two transparent oxides as front electrodes were fabricated, and the correlation between humidity resistance of transparent electrodes and device performance of solar cells was examined. When both transparent electrodes were exposed to high temperature distilled water, they showed a rapid increase in sheet resistance and a decrease in the fill factor of the solar cell. However, AZO showed a drastic decrease in efficiency at the beginning of exposure, while GAZO showed that the deterioration of efficiency occurred over a long period of time and that the long term moisture resistance of GAZO was better.

• Journal of the Korean Electrochemical Society
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• v.22 no.2
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• pp.60-68
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• 2019

High-voltage operation of the lithium ion battery is one of the advantageous approaches to obtain high energy capacity without changing the conventional cell components and structure. However, operating at harsh condition inevitably results in severe side reactions at the electrode surface and structural disintegration of active material particles. Herein we coated layers composed of $Al_2O_3$ and ZnO on the electrode based on NCM using atomic layer deposition (ALD). Thicker layers of novel Al-doped ZnO (AZO) coating compared to conventional ALD coated layers are prepared. Cathode based on NCM with the varying AZO coating thickness are fabricated and used for coin cell assembly. Effect of ALD coating thickness on the charge-discharge cycle behavior obtained at high-voltage operation was investigated.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.178-178
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• 2010

We have deposited aluminum-doped ZnO thin films on borosilicate glass by atomic layer deposition. Diethylzinc (DEZ) and dimethylaluminum isopropoxide (DMAIP) were used as the metal precursor and the Al-dopant, respectively. Water was used as an oxygen source. DMAIP was successfully used as an aluminum precursor for chemical vapor deposition and ALD. All deposited films showed n-type conduction. The resistivity decreased to a minimum and then increased with increasing the aluminum content. The carrier concentration increased and the carrier mobility decreased with increasing the DMAIP to DEZ pulse ratio. The average optical transmittance was nearly 80 % in the visible part of the spectrum. The absorption edge moved to the shorter wavelength region with increasing the DMAIP to DEZ pulse ratio. Our results indicate that DMAIP is suitable for Al doping of ZnO films.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.420-420
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• 2012

ZnO seed layer were deposited on quartz substrate by sol-gel method and prism-like Al-doped ZnO nanorods (AZO nanorods) were grown on ZnO seed layer by hydrothermal method with various Al concentration ranging from 0 to 2.0 at.%. Structural and optical properties of the AZO nanorods were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), photoluminescence (PL). The diameter of the AZO nanorods was smaller than undoped ZnO nanorods and its diameter of the AZO nanorods decreased with increasing Al concentration. In XRD spectrum, it was observed that stress and full width at half maximum (FWHM) of the AZO nanorods decreased and the 'c' lattice constant increased as the Al concentration increased. From undoped ZnO nanorods, it was observed that the green-red emission peak of deep-level emission (DLE) in PL spectra. However, after Al doping, not only a broad green emission peak but also a blue emission peak of DLE were observed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.328-331
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• 2000

The effect of the constituent elements and their composition of the seed layer on the properties of the evaporated Zn thin films was investigated. It was carried out by the analysis of the preferred orientation and the grain size, and the corrosion characteristics. Seed layers were prepared by evaporation of Al and AlCu respectively, and here the Cu content as additives of the source materials of seed layers were designed 5 a/o to 20 a/o. The values of full width at half maximum (FWHM) of the (002) x-ray diffraction peaks of Zn decreased by increasing the amount of the additives on Al seed layer, as a results, the grain sizes also decreased. In order to characteristics of Zn thin films evaporated on the various seed layers, electrical resistivity changes with a function of time at the temperature of 40$^{\circ}C$ and the relative humidity of 80%, as a result, the relative resistivity changes were increased by decreasing the grain size and the FWHM values of (002) peaks of Zn.

• Journal of Information Display
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• v.10 no.4
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• pp.137-142
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• 2009

Transparent top-gate Al-Zn-Sn-O (AZTO) thin-film transistors (TFTs) with an $Al_2O_3$ protective layer (PL) on an active layer were studied, and a transparent 2.5-inch QCIF+AMOLED (active-matrix organic light-emitting diode) display panel was fabricated using an AZTO TFT backplane. The AZTO active layers were deposited via RF magnetron sputtering at room temperature, and the PL was deposited via two different atomic-layer deposition (ALD) processes. The mobility and subthreshold slope were superior in the TFTs annealed in vacuum and with oxygen plasma PLs compared to the TFTs annealed in $O_2$ and with water vapor PLs, but the bias stability of the TFTs annealed in $O_2$ and with water vapor PLs was excellent.