Layer-by-layer morphology is a crucial signature of the quality of epitaxial thin films. In this study, layer-by-layer growth of an ε-phase gallium oxide (ε-Ga2O3) thin film is demonstrated using metal–organic chemical vapor deposition. A two-step growth method, in which a nucleation layer is grown at 600 °C and an epilayer is grown at 640 °C, is employed to fabricate a high-quality ε-Ga2O3 thin film on a c-plane sapphire substrate. The morphology of the ε-Ga2O3 film is evaluated by atomic force microscope. The density of screw-type threading dislocations determined by an X-ray diffraction rocking curve is as low as 1.8 × 108 cm−2.

Diabetes is a metabolic disorder characterized by hyperglycemia due to defective insulin secretion or its biological dysfunction. However, frequent subcutaneous injection of insulin often results in discomfort and local tissue infection. Herein, we demonstrate the successful fabrication of a mini-tablet system based on self-propelled micromotors with biocompatibility and biodegradability for oral colon administration of insulin. The insulin layer is first constructed onto the surface of a magnesium based micromotor via electrostatic interactions, followed by a tableting process. The resulting mini-tablets are then coated with esterified starch with colonic degradation capability, thus achieving controlled release of the embedded micromotors in the colon region. In the meantime, autonomous movement of the released micromotors with a speed up to 76.22 μm·s–1 further results in enhanced colonic uptake and absorption of insulin, realizing long-term control of blood glucose for more than 5 h. Our micromotor based mini-tablet system can not only broaden the biomedical applications of emerging self-propelled micromotors but also offer an appealing strategy for oral administration of biomacromolecular drugs represented by insulin.

In this work, high mobility indium tin oxide (ITO) thin films with uniform crystallographic orientation are prepared. These films present a wide-range transmittance window and could be used as transparent electrodes at ultraviolet-visible-infrared wavelengths. In particular, the ITO thin film is characterized by low resistivity (5.1 × 10 Ωcm) and high infrared transmittance (88.5% at 2.5 μm) due to the improved mobility, achieving higher infrared performance than other transparent conductive materials. A model based on carrier's transport theory and Lorentz-Drude dielectric function is proposed to quantitatively calculate the optical performance of conductive thin films under the influence of plasma effect. The calculation demonstrates that ITO is a suitable electrode material for near/middle infrared optoelectronic applications.

No abstract

No abstract