• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.172-175
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• 2003

ZnO:Al thin film for application to FBAR's bottom electrode using ZnO piezoelectric thin film were prepared by FTS, in order to improve the crystallographic properties of ZnO thin films because the ZnO:Al thin film and ZnO thin films structure is equal each other. So we prepared the ZnO:Al thin film with oxygen gas flow rate. Thickness and c-axis preferred orientation and electric properties of ZnO:Al bottom electrode were evaluated by $\alpha$-step, XRD and 4-point probe..

• Journal of the Korean Ceramic Society
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• v.45 no.3
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• pp.139-141
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• 2008

The piezoelectric properties of tetragonal 0.88Pb$(Zn_{1/3}Nb_{2/3)O_3-0.12PbTiO_3$ single crystals are characterized along the <111> direction, which composed the engineering domain configuration in the tetragonal phase. The <111>-oriented crystal possessed smaller $d_{33}$ values compared to the crystal along the <001> spontaneous polarization direction. Based on phenomenological theory, it is shown that the engineering domain configuration does not enhance the piezoelectric constant in tetragonal 0.88Pb$(Zn_{1/3}Nb_{2/3)O_3-0.12PbTiO_3$ single crystals. In addition, the electrostrictive coefficients of $Q_{12}=-0.03706m^4/C^2,\;Q_{11}=0.10765m^4/C^2,\;and\;Q_{44}=0.02020m^4/C^2$ of tetragonal 0.88PZN-0.12PT single crystals were calculated.

• Advances in nano research
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• v.12 no.6
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• pp.593-603
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• 2022

The critical buckling temperature rise of a newly proposed piezoelectrically active sandwich plate (ASP) has been investigated in this work. This structure includes a porous polymeric layer integrated between two piezoelectric nanocomposite layers. The piezoelectric material is made of a passive polymeric material that is activated by lead-free nanowires (NWs) of zinc oxide (ZnO) embedded inside the matrix. In both nanocomposite layers and porous core, functional graded (FG) patterns have been considered for the distributions of ZnO NWs and voids, respectively. By adopting a higher-order theory of plates, the governing equations of thermal buckling are obtained. This set of equations is then treated using an extended mesh-free solution. The effects of plate dimensions, porosity states, and the nanowire parameters have been investigated on the critical buckling temperature rises of the proposed lightweight ASPs with different boundary conditions. The results disclose that the use of porosities in the core and/or mixing ZnO NWs in the face sheets substantially arise the critical buckling temperatures of the newly proposed active sandwich plates.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.237-237
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• 2009

Zinc oxide (ZnO) thin film was deposited on Si substrates using polycrystalline (poly) 3C-SiC buffer layer, in which the ZnO film was grown by sol-gel method. Physical characteristics of the grown ZnO film was investigated experimentally by means of SEM, XRD, FT-IR (Furier Transform-Infrared spectrum), and AFM. XRD pattern was proved that the grown ZnO film on 3C-SiC layers had highly (002) orientation with low FWHM (Full width of half maxium). These results showed that ZnO thin film grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.125-130
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• 2006

The optical gain and the luminescence of a ZnO quantum well with MgZnO barriers is studied theoretically. We calculated the non-Markovian optical gain and the luminescence for the strained-layer wurtzite quantum well taking into account of the excitonic effects. It is predicted that both optical gain and luminescence are enhanced for the ZnO quantum well when compared with those of InGaN-AlGaN quantum well structure due to the significant reduction of the piezoelectric effects in the ZnO-MgZnO systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.428-430
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• 2009

C-axis-oriented ZnO thin films were successfully deposited on p-Si (100) in an RF magnetron sputtering system. Deposition conditions such as deposition power, working pressure, and oxygen gas ratio were varied. Crystalline structures of the deposited ZnO films were investigated by a scanning electron microscope (SEM) technique. Results show that the deposition parameters can have a strong impact on the preferred orientations and grain sizes of the deposited ZnO films.

• Electrical & Electronic Materials
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• v.9 no.4
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• pp.351-356
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• 1996

The quartemary system ceramics 0.5[xPb(Zn$_{1}$3/Nb$_{2}$3/)O$_{3}$-(1-x)Pb(Ni$_{1}$3/Nb$_{2}$3/)O$_{3}$]-0.5[yPbTiO$_{3}$-(1-y) PbZrO$_{3}$ for piezoelectric actuators were prepared bv the were added to the raw materials up to 5 mole. Sintering temperature was varied form 1000.deg. C to 1200.deg. C. Sintering characteristrics, dielectric and piezoelectric properties were then investigated. Piezoelectric properties of sample prepared by the molten salt method were improved compared to those prepared by the conventional method. Addition of PZN shifted morphotropic phase boundary to more Zr-rich composition and decreased the piezoelectric properties.

• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1108-1114
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• 1999

Microstructure and electrical properties of ZnO-doped (0-5 mol%) 0.05 Pb(Mn1/3Sb2/3)O3-0.95 PZT ceramics were investigated. Sintering temperature was decreased to 100$0^{\circ}C$ due to eutetic reaction between PbO and ZnO. Grain-size increased up to adding 1mol% ZnO and then decreased. Compositions of grain and grain-boundary were investigated by WDS. Lattice parameter was decreased with ZnO addition. Density increased with ZnO addition and reached to the maximum of 7.84(g/cm2) at 2 mol% ZnO. The effect of ZnO on electrical properties of PMS-PZT was investigated. At 3mol% ZnO addition electromechanical coupling factor(kp) was about 50% and relative dielectric constant($\varepsilon$33/$\varepsilon$0) was 997 Mechanical quality factor(Qm) decreased with ZnO addition. Lattice parameters and tetragonality(c/a) were measured to investigate relationship between the electric properties and substitution of Zn2+. At 3 mol% ZnO tetragonality was maximiged at c/a=1.0035 Curie temperature (Tc) decreased slightly with ZnO addition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.422-425
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• 2004

In this study, the AZO thin films were prepared as a function of oxygen gas flow ratio at room temperature by FTS(Facing Targets Sputtering) apparatus using Zn:Al(metal)-Zn:Al(metal) or Zn(metal)-ZnO:Al(ceramic). The film thickness, crystalline and electric properties of AZO thin film was evaluated by $\alpha$-step, XRD and 4-point probe. In the results, the resistivity of AZO thin film was shown the lowest value about 8${\times}$10$^{-2}$ $\Omega$-cm(Zn:Al-Zn:Al), 3${\times}$10$^{-1}$ $\Omega$-cm(Zn-ZnO:Al) at the oxygen gas flow ratio 0.3. And the AZO thin film has good crystalline at oxygen gas flow ration 0.4, using Zn:Al-Zn:Al targets.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1414-1415
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• 2006

Air-gap type film bulk acoustic wave resonator device using ZnO for piezoelectric layer and sacrifice layer, deposited by RF magnetron sputter with various conditions, fabricated in this study. Also, membrane$(SiO_2)$ and top and bottom electrode(both Al) of piezoelectric layer deposited by RF magnetron sputter. Using micro electro mechanical systems(MEMS) technique, sacrifice layer removed and then air-gap formed. The results of each process checked by XRD, AFM, SEM to obtain good quality device.