• Journal of the Korean Society for Heat Treatment
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• v.31 no.3
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• pp.111-119
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• 2018

We report the post-annealing effect of Sn doped ZnO (ZnO:Sn) thin film grown on sapphire (001) substrate using radio-frequency powder sputtering method. During thermal annealing in a vacuum atmosphere, the ZnO:Sn thin film is transformed into a porous thin film. Based on X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analyses, a possible mechanism for the production of pores is presented. Sn atoms segregate to form clusters that act as catalysts to dissociate Zn-O bonds. The Zn and O atoms subsequently vaporize, leading to the formation of pores in the ZnO:Sn thin film. We also found that Sn clusters were oxidized to form SnO or $SnO_2$ phases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.641-646
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• 2011

Ga-doped ZnO-$SnO_2$ (ZSGO) films were deposited by rf magnetron sputtering and their structural and electrical properties were investigated. In order to fabricate the target for sputtering, the mixture of ZnO, $SnO_2$ (1:1 weight ratio) and $Ga_2O_3$ (3.0 wt%) powder was calcined at $800^{\circ}C$ for 1 h. The substrate temperature was varied from room temperature to $300^{\circ}C$. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The optical transmittances of the films were measured and the optical energy band gaps were obtained from the absorption coefficients. The resistivity variation with substrate temperature was measured. Auger electron spectroscopy was employed to find the atomic ratio of Zn, Sn, Ga and O in the film deposited at room temperature. ZSGO films exhibited the optical transmittance in the visible region of more than 80% and resistivity higher than $10\;{\Omega}cm$.

• Journal of Electrochemical Science and Technology
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• v.10 no.1
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• pp.61-68
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• 2019

Well aligned $SnO_2$-doped ZnO nanorods were prepared by single step or 2-step electrochemical depositions in a mixture solution of zinc nitrate hexahydrate, ammonium hydroxide solution and 0.1 M tin chloride pentahydrate. The morphologies of electrochemically deposited $SnO_2$-doped ZnO were transformed from plain (or network) structures at low reduction potential to needles on hills at high reduction potential. Well aligned ZnO was prepared at intermediate potential ranges. Reduction reagent and a high concentration of Zn precursor were required to fabricate $SnO_2$ doped ZnO nanorods. When compared to results obtained by single step electrochemical deposition, 2-step electrochemical deposition produced a much higher density of nanorods, which was ascribed to less potential being required for nucleation of nanorods by the second-step electrochemical deposition because the surface was activated in the first-step. Mechanisms of $SnO_2$ doped ZnO nanorods prepared at single step or 2-step was described in terms of applied potential ranges and mass-/charge- limited transfer.

• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.21-24
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• 2017

Usually, the oxygen vacancy is an important factor in an oxide semiconductor device because the conductivity is related to the oxygen vacancy, which is formed at the interface between oxide semiconductors and electrodes with an annealing processes. ZTO is made by mixing n-type ZnO and p-type $SnO_2$. Zink tin oxide (ZTO), zink oxide (ZnO) and tin oxide ($SnO_2$) thin films deposited by RF magnetron sputtering and annealed, to generate the oxygen vacancy, were analyzed by XPS spectra. The contents of oxygen vacancy were the highest in ZTO annealed at $150^{\circ}C$, ZnO annealed at $200^{\circ}C$ and $SnO_2$ annealed at $100^{\circ}C$. The current was also increased with increasing the oxygen vacancy ions. The highest content of ZTO oxygen vacancies was obtained when annealed at 150. This is the middle level in compared with those of ZnO annealed at $200^{\circ}C$ and $SnO_2$ annealed at $100^{\circ}C$. The electrical properties of ZTO followed those of $SnO_2$, which acts a an enhancer in the oxide semiconductor.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.165-172
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• 1997

CRT용 고전압 형광체인 ZnS를 저전압용에 적용하기 위해 ZnS 분말표면에 졸-겔법으로 SnO$_2$코팅조건을 연구하였다. Sn의 코팅량은 Sn/ZnS=0.02~0.07 범위에서 변화시켰으며, 코팅된 ZnS분말의 열처리는 450~90$0^{\circ}C$/2hr 범위에서 수행하였다. Sn/ZnS=0.035일 때 최적의 코팅이 이루어졌으며, 과도한 열처리는 ZnS에서 ZnO로 상전이가 발생하므로 500~$600^{\circ}C$ 정도가 안전한 조건임이 규명되었다. Sn량이 증가할수록 코팅된 ZnS의 형광강도는 감소하였으나 저전압 형광특성은 향상될 수 있는 가능성을 보여주었다.

• Korean Journal of Materials Research
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• v.14 no.3
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• pp.224-228
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• 2004

Respectively the powder made of ZnO added $SnO_2$ was prepared by coprecipitation method and the thick film gas sensor was fabricated by screen-printing technique, The morphology and phase of the powder and film was investigated by SEM and XRD. The specific area of the particle was linearly increased with ZnO contents. Target gas was di(propylene glycol) methylether ($CH_3$($OC_3$$H_{6}$ )$_2$OH, DPGME), which is simulant gas of blister gas. The gas sensing characteristics for DPGME were examined with flow type measurement system and the concentrations of target gas were controlled from 500 ppb to 1500 ppb. ZnO (2 wt%) added $SnO_2$ showed maximum sensitivity to DPGME at $300^{\circ}C$.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1455-1458
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• 1997

In order to promote CO gas sensitivity, $SnO_2$ added ZnO prepared. The electrical conductivities and dielectric constants decreased by increasing $SnO_2$ content in air. The electrical conductivities in 1000ppm CO atmosphere were larger than in dry air. The measured CO sensitivities were $1{\sim}15.2$ at $100^{\circ}C{\sim}480^{\circ}C$. The maximum CO sensitivity of 15mol% $SnO_2$ added ZnO was 15.2 at $305^{\circ}C$.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.155.2-155
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.173-173
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• 2002

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.107.2-107
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• 2002