Effect of H/Ar treatment on ZnO:B transparent conducting oxide for flexible a-Si:H/μc-Si:H photovoltaic modules under damp heat stress

Jeong, J.S.,Kim, Y.H.,Park, C.K.,Kim, H.D.,Choi, J. Pergamon Press 2016 Microelectronics and reliability Vol.64 No.-

<P>A flexible amorphous/microcrystalline Si:H (a-Si:H/mu c-Si:H) tandem-junction photovoltaic (PV) module was produced in which a thin film of ZnO:B grown by metalorganic chemical vapor deposition (MOCVD) served as the transparent conducting oxide (TCO). The Hall mobility of ZnO:B is degraded by damp heat, simulated here using the conditions of 85 degrees C at 85% relative humidity; this affects the series resistance and efficiency of the PV module. In this study, ZnO:B was treated by H/Ar plasma to reduce the degradation experienced under damp heat. The degradation time of the Hall mobility of ZnO:B, defined as the time necessary for the cell to reach the efficiency loss of -20%, was improved by similar to 54% by H/Ar treatment (ZnO:B center dot H/Ar). The mechanism behind this improvement was investigated by assessing the reactions of the ZnO:B and ZnO:B center dot H/Ar thin films to moisture. Related changes in the physical and chemical properties of ZnO:B and ZnO:B center dot H/Ar were analyzed by Xray photoelectron spectroscopy, secondary-ion mass spectroscopy, and ultraviolet photoelectron spectroscopy. The analyses showed that the concentration of OH- was high while those of Zn2+ and B3+ were low in the grain boundaries of the ZnO:B surface after exposure to humidity. After H/Ar treatment, the increase in OH- concentration in ZnO:B was reduced, and the decrease in the Zn2+ and B3+ concentrations was much smaller. The H/Ar plasma treatment of ZnO:B affected the surface reaction forming Zn(OH)(2), between the OH- and Zn2+ ions at the grain boundaries under damp heat. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Effect of Heat Treatment Method on Properties of ZnO Thin Films Deposited by RF Magnetron Sputtering

김덕규 한국진공학회 2017 Applied Science and Convergence Technology Vol.26 No.2

ZnO thin films which were deposited by RF magnetron sputtering system were annealed by furnace and insitu heat treatment methods. We investigated the effect of heat treatment method on physical properties of ZnO thin films. The structural and optical properties of ZnO thin films were improved by heat treatment. Through the annealing treatment of ZnO film by furnace, the good crystallinity and ultraviolet emission were obtained. These results are attributed to the improved formation of Zn-O bond in ZnO thin film annealed at by furnace. We confirm that the formation of Zn-O bond plays an important role in obtaining the excellent structural and optical properties of ZnO thin films.

Effect of Heat Treatment Method on Properties of ZnO Thin Films Deposited by RF Magnetron Sputtering

Kim, Deok Kyu The Korean Vacuum Society 2017 Applied Science and Convergence Technology Vol.26 No.2

ZnO thin films which were deposited by RF magnetron sputtering system were annealed by furnace and insitu heat treatment methods. We investigated the effect of heat treatment method on physical properties of ZnO thin films. The structural and optical properties of ZnO thin films were improved by heat treatment. Through the annealing treatment of ZnO film by furnace, the good crystallinity and ultraviolet emission were obtained. These results are attributed to the improved formation of Zn-O bond in ZnO thin film annealed at by furnace. We confirm that the formation of Zn-O bond plays an important role in obtaining the excellent structural and optical properties of ZnO thin films.

Effects of Heat Treatment on the Dye Adsorption of ZnO Nanorods for Dye-sensitized Solar Cells

윤원석,최석철,손상호,오상진 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.9

Well-aligned ZnO nanorods for the photoelectrode of dye-sensitized solar cells(DSSCs) were grown via a sonochemical method and the heat-treatment effects on the dye adsorption in DSSCs were studied. The heat-treatment of well-aligned ZnO nanorods was performed at 200 ~ 500 ℃ for 1h, immediately followed by the dye adsorption. The dye amounts adsorbed in ZnO nanorods were estimated from a UV-Vis absorbance, using Beer-Lambert’s law. The efficiency of DSSCs with ZnO nanorods was measured to investigate the heat-treatment effects of ZnO nanorods on the dye adsorption properties. It is found that the heat-treatment of ZnO nanorods yields a change in their dye adsorption ability, resulting in the change in the efficiency of DSSCs.

In Situ Heat Treatment of ZnO:Al Thin Films Fabricated by RF Magnetron Sputtering

Kim, Deok Kyu The Korean Institute of Electrical and Electronic 2017 전기전자재료학회논문지 Vol.30 No.5

ZnO:Al thin films were deposited on glass substrate by RF magnetron sputtering followed by in situ heat treatment in the same chamber. Effects of in situ heat treatment on properties of ZnO:Al thin films were investigated in this study. As heat treatment temperature was increased, crystal quality was improved first and then it was deteriorated, surface roughness was decreased, and sheet resistance was also decreased. The decrease in sheet resistance was caused by increasing carrier concentration due to decreased surface roughness. The decrease in surface roughness resulted in increase of transmittance. Therefore, in situ heat treatment is an effective method for obtaining films with better electrical characteristics.

열처리에 따른 MWCNT/ZnO 복합체 필름 가스센서의NOX 가스 검출 특성

김현수,장경욱 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.7

In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. In this study,we fabricated a NOX gas sensor by using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was then treated by a 450℃ temperature process to increase its detectionsensitivity for NOx gas. We compared the detection characteristics of a ZnO film gas sensor, MWCNT film gas sensor,and the MWCNT/ZnO composited film gas sensor with and without the heat-treatment process. The fabricated gassensors were used to detect NOX gas at different concentrations. The gas sensor absorbed NOX gas molecules, exhibitingincreased sensitivity. The sensitivity of the gas sensor was increased by increasing the gas concentration. Additionally,while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained itssensitivity for detecting NOX gas. Compared with ZnO, the MWCNT film gas sensor is excellent for detecting NOX gas. From the experimental results, we confirmed the enhanced gas sensor sensing mechanism. The increased effect byelectronic interaction between the MWCNT and ZnO films contributes to the improved sensor performance.

열처리에 따른 MWCNT/ZnO 복합체 필름 가스센서의 NO_X 가스 검출 특성

김현수,장경욱,Kim, Hyun-Soo,Jang, Kyung-Uk 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.7

In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. In this study, we fabricated a $NO_X$ gas sensor by using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was then treated by a $450^{\circ}C$ temperature process to increase its detection sensitivity for NOx gas. We compared the detection characteristics of a ZnO film gas sensor, MWCNT film gas sensor, and the MWCNT/ZnO composited film gas sensor with and without the heat-treatment process. The fabricated gas sensors were used to detect $NO_X$ gas at different concentrations. The gas sensor absorbed $NO_X$ gas molecules, exhibiting increased sensitivity. The sensitivity of the gas sensor was increased by increasing the gas concentration. Additionally, while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained its sensitivity for detecting $NO_X$ gas. Compared with ZnO, the MWCNT film gas sensor is excellent for detecting $NO_X$ gas. From the experimental results, we confirmed the enhanced gas sensor sensing mechanism. The increased effect by electronic interaction between the MWCNT and ZnO films contributes to the improved sensor performance.

In Situ Heat Treatment of ZnO:Al Thin Films Fabricated by RF Magnetron Sputtering

김덕규 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.5

ZnO:Al thin films were deposited on glass substrate by RF magnetron sputtering followed by in situ heattreatment in the same chamber. Effects of in situ heat treatment on properties of ZnO:Al thin films wereinvestigated in this study. As heat treatment temperature was increased, crystal quality was improved first and thenit was deteriorated, surface roughness was decreased, and sheet resistance was also decreased. The decrease in sheetresistance was caused by increasing carrier concentration due to decreased surface roughness. The decrease in surfaceroughness resulted in increase of transmittance. Therefore, in situ heat treatment is an effective method for obtainingfilms with better electrical characteristics.

RF-Sputtering 법을 이용한 ZnO:Al 박막의 후 열처리에 따른 특성 변화

이재형,이동진,Lee, Jae-Hyeong,Lee, Dong-Jin 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.9

Zinc oxide (ZnO) has been widely studied for its practical applications such as transparent conduction electrodes for flat panel displays and solar cells. Especially, ZnO films show good chemical stability against hydrogen plasma, absence of toxicity, abundance in nature, and then suitable for photovoltaic applications. However, the fabrication process of thin film solar cells require a high substrate temperature and/or post heat treatment. Therefore, the layers have to withstand high temperatures, requiring an excellent stability without degrading their electronic and optical properties. In this paper, we investigated the stability of zinc oxide (ZnO) films doped with aluminum and hydrogen. Doped ZnO films were prepared by r.f. magnetron sputter and followed by heat treatment at different temperatures and for various times.

Influences of Heat Treatment on the Optical Properties of ZnO Nanorods

판더롱 한국물리학회 2011 새물리 Vol.61 No.6

ZnO nanorods grown by using an aqueous solution method were annealed in an oxygen ambient at various temperatures in the range of T_a =300-1000℃. Their optical properties were then studied by using photoluminescence and Raman scattering spectrometers. The experimental results revealed that the peak positions of the ultraviolet emission and of the vibrational-phonon modes were independent of T_a, indicating the stability of the ZnO nanorods in the wurtzite structure. However, the intensity of visible emissions changed strongly as a function of T_a. This is assigned to lattice defects and/or impurities generated from precursors during the crystal growth and heat treatment. Particularly,annealing temperatures greater than 300℃ lead to a decomposition and escape of impurities from the ZnO nanorods, thus improving their crystal quality.