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A study of the structure based on the ZnO layers and NKN-SrTiO 3 (NKN-ST) ceramic substrates with different sputtering conditions to deposit ZnO films is presented. Poly-crystal ZnO films with c-axis (002) orientation have been successfully grown on the NKN-ST ceramic substrates by RF magnetron sputtering technique. The deposited films were characterized as a function of oxygen-argon gas flow ratio, RF power, sputtering pressure, and depositing time. The ZnO films with strong (002) orientation are obtained under a base pressure of 20 mTorr, containing 40% oxygen and 60% argon at RF power of 60 W. Crystalline structures and surface roughness characteristics of the films were investigated by using XRD analysis, SEM, and AFM measurements. It shows that the preferred oriented ZnO film is beneficial for improving the electromechanical coupling coefficient (k 2 ) of Surface Acoustic Wave (SAW) device. The velocity, k 2 , and temperature coefficient of frequency of the ZnO/IDT/NKN-ST SAW device properties are 3120 m/s, 4.20%, and À320, respectively.

Electron injection and transport are key issues in the performance of organic light-emitting diodes (OLEDs). In this paper, an efficient n-doped electron transport layer (ETL) composed of 4,7-diphenyl-1,10-phenanthroline (Bphen) and lithium acetate (CH3COOLi) is demonstrated. The results reveal that the Fermi level moves toward the lowest unoccupied molecular orbital (LUMO), which consequently reduces the electron injection barrier and further enhances the efficiency of electron injection from the aluminum cathode. The mobility of electrons in the Bphen layer increased with CH3COOLi doping. In addition, a sky-blue fluorescent OLED was fabricated using the CH3COOLi-doped Bphen ETL, exhibiting a high luminance and efficiency. We also proved that as an n-type dopant, LiAC is more capable than LiF.

In this paper, the effects of ZnO doping on the piezoelectric and ferroelectric properties of lead-free Na0.5K0.5Nb0.97Sb0.03O3 -2% CuO -x% ZnO (NKNSCZ) piezoelectric ceramics were systematically investigated. NKNSCZ ceramics were synthesized using the conventional solid-state reaction method. ZnO additions had not only enhanced the piezoelectric properties kp, Qm value by interacting with CuO to form liquid phase but lowered the sintering time as well. Relatively high piezoelectric properties were obtained at x = 1.5 with kp = 0.427, kt = 0.44, ɛr = 235, Qm = 1613, tan δ = 0.45%, and density = 4.56 g/cm3 respectively.