A Study of Microstructural Models of Li-doped ZnO Ceramic for Piezoelectric Application

Structural and microstructural properties of Zn1-xLixO (0.00 ≤x≤ 0.50) ceramics were carried out using X-ray Diffraction (XRD) showed that the samples were polycrystalline with hexagonal wurtzite structure. The average crystallite size was estimated using three models, all of which showed decrement with increased lithium-doping. The crystallite size increased systematically, with the largest value being 200 nm in the Li-doped ZnO in x=0.3. However, microstrain was fairly constant for all doped samples with a value of ~0.006, the value for the pristine being 0.001. Of the three models, the comparison showed that the Scherer model had the smallest crystallite size due to the neglect of strain, whereas the W-H model had the largest in the doped samples, with crystallite size ~200 nm, but with subsequent decrease observed which is attributed to the assumption of isotropy in the model. The c/a ratio indicated a consistent hexagonal structure despite lithium-doping. Energy Dispersive Spectroscopy (EDS) showed that all the nominal elements compositions were present. A decrease in grain size with the increase in lithium-doping was observed with the lowest grain size (0.2 μm) observed in x=0.5, thus making it the specimen with the highest potential for piezoelectric application.

Preparation of Li-Doped Indium-Zinc Oxide Thin-Film Transistor at Relatively Low Temperature Using Inkjet Printing Technology

Inkjet printing is a very attractive technology for printed electronics and a potential alternative to current high cost and multi-chemical lithography processes, for display and other applications in the electronics field. Inkjet technology can be employed to fabricate organic light emitting diodes (OLED), quantum dots displays, and thin-film transistors (TFTs). Among potential applications, metal oxide TFTs, which have good properties and moderate processing methods, could be prepared using inkjet printing in the display industry. One effective method of improving their electrical properties is via doping. Lithium doping an oxide TFT is a very delicate process, and difficult to get good results. In this study, lithium was added to indium-zinc oxide (IZO) for inkjet printing to make oxide TFTs. Electrical properties, transfer and output curves, were achieved using inkjet printing even at the relatively low annealing temperature of 200 oC. After optimizing the inkjet process parameters, a 0.01 M Li-doped IZO TFT at 400 oC showed a mobility of 9.08 ± 0.7 cm2/V s, a sub-threshold slope of 0.62 V/dec, a threshold voltage of 2.66 V, and an on-to-off current ratio of 2.83 × 108. Improved bias stability and hysteresis behavior of the inkjet-printed IZO TFT were also achieved by lithium doping.

Hydrogen Sorption Behaviors on Lithium Doped MIL@53-Al at Non-Cryogenic Temperatures.

The current research work reports the methods that have been developed to dope the Lithium nanoparticles to the MIL@53-Al surface frameworks without inducing the structures. The prepared MIL@53-Al MOFs and Li/MIL/53-Al were characterized by XRD, TEM, SEM, BET, and TGA. The developed Lithium doped MIL@53-Al and MIL@53-Al were measured for the hydrogen sorption capacities at 298 and 253 K under a pressure of 75 bar. The study reports revealed that sorption capacities of MIL@53-Al enhanced significantly due to the doping of lithium ions; however, doping of these ions should be controlled for obtaining good uptake capacities as the higher concentrations of lithium might damage the frameworks of the synthesized materials. The lithium doping enhances the hydrogen uptake from 1.37 to 1.75 wt % at 253 K and 75 bar pressure.