Insulator-to-semiconductor conversion of solution-processed ultra-wide bandgap amorphous gallium oxide via hydrogen annealing

Developing semiconducting solution-processed ultra-wide bandgap (UWB) amorphous oxide semiconductor (AOS) is an emerging area of research interest. However, obtaining electrical conduction on it is quite challenging. Here, we demonstrate the insulator-to-semiconductor conversion of solution-processed a-Ga2Ox (Eg~4.8 eV) through hydrogen annealing. The successful conversion was reflected by the switching thin-film transistor (TFT) with μsat of 10-2 cm2/Vs. We showed that H incorporated after hydrogen annealing acts as a shallow donor which increased the carrier concentration and shifted the EF closer to the CBM.

The Effects of Hydrogen Annealing on Carbon Nanotube Field-Effect Transistors

We have systematically investigated the effects of hydrogen annealing on Ni- and Al-contacted carbon nanotube field-effect transistors (CNTFETs), whose work functions have not been affected by hydrogen annealing. Measured results show that the electronic properties of single-walled carbon nanotubes are modified by hydrogen adsorption. The Ni-contacted CNTFETs, which initially showed metallic behavior, changed their p-FET behavior with a high on-current over 10 µA after hydrogen annealing. The on-current of the as-made p-FETs is much improved after hydrogen annealing. The Al-contacted CNTFETs, which initially showed metallic behavior, showed unipolar p-FET behavior after hydrogen annealing. We analyzed the energy band diagrams of the CNTFETs to explain experimental results, finding that the electron affinity and the bandgap of single-walled carbon nanotubes changed after hydrogen annealing. These results are consistent with previously reported ab initio calculations.

THE EFFECT OF IRON ON THE SURFACE GRAPHITIZATION OF SILICON CARBIDE

In order to decrease the decomposition temperature of SiC, 12[Formula: see text]nm Fe thin film is applied on SiC substrates as a catalyst layer using electron beam (e-beam) deposition. To investigate the mechanism of Fe-treated SiC decomposition, local Fe regions are formed through dewetting of the catalyst layer by hydrogen annealing. The results show that Fe decreases the decomposition temperature of SiC effectively and increases the kinetics of the graphitization. Studies showed that depending on the amount of Fe, crumpled and ordered graphene films can be synthesized simultaneously on SiC by using this method.

Photoinduced Defect Engineering: Enhanced Photocatalytic Performance of 3D BiOCl Nanoclusters with Abundant Oxygen Vacancies

Oxygen vacancies are highly important for photocatalytic performance in bismuth oxychloride, but their preparation is limited to vacuum roasting and hydrogen annealing techniques at high temperatures (200-400℃). Here we report...