We establish a powerful poly(4-styrenesulfonate) (PSS)-treated strategy for sulfur vacancy healing in monolayer MoS2 to precisely and steadily tune its electronic state. The self-healing mechanism, in which the sulfur vacancies are healed spontaneously by the sulfur adatom clusters on the MoS2 surface through a PSS-induced hydrogenation process, is proposed and demonstrated systematically. The ...

This study examined the performance and photo-bias stability of double-channel ZnSnO/InZnO (ZTO/IZO) thin-film transistors. The field-effect mobility (μFE) and photo-bias stability of the double-channel device were improved by increasing the thickness of the front IZO film (t(int)) compared to the single-ZTO-channel device. A high-mobility (approximately 32.3 cm(2)/Vs) ZTO/IZO transistor with e...

Traditional nanostructured design of cerium oxide catalysts typically focuses on their shape, size, and elemental composition. We report a different approach to enhance the catalytic activity of cerium oxide nanostructures through engineering high density of oxygen vacancy defects in these catalysts without dopants. The defect engineering was accomplished by a low pressure thermal activation pr...

True n-type doping of titanium oxide without formation of midgap states would expand the use of metal oxides for charge-based devices. We demonstrate that plasma-assisted fluorine insertion passivates defect states and that fluorine acts as an n-type donor in titanium oxide. This enabled us to modify the Fermi level and transport properties of titanium oxide outside the limits of O vacancy dopi...

Point defect species and concentrations in metastable Fe-C alloys are determined using density functional theory and a constrained free-energy functional. Carbon interstitials dominate unless iron vacancies are in significant excess, whereas excess carbon causes greatly enhanced vacancy concentration. Our predictions are amenable to experimental verification; they provide a baseline for rationa...

We demonstrate that the internal magnetic states of a single nitrogen-vacancy defect, within a rotating diamond crystal, acquire geometric phases. The geometric phase shift is manifest as a relative phase between components of a superposition of magnetic substates. We demonstrate that under reasonable experimental conditions a phase shift of up to four radians could be measured. Such a measurem...

We show that electron correlations control the photophysics of defects in SiC through both renormalization of the quasiparticle band structure and excitonic effects. We consider the carbon vacancy with two possible excitation channels that involve conduction and valence bands. Corrections to the Kohn-Sham ionization levels strongly depend on the defect charge state. Excitonic effects introduce ...

The native point defects in Fe2O3 are theoretically investigated using ab initio methods based on the GGA + U formalism. We consider vacancies and interstitials of Fe and O atoms as well as the electron polaron as Fe(II) defects at the host Fe(III) site. The formation energies and charge transition levels are computed for each defect type with careful elimination of size effects of the supercel...

Coexistence of polarization and resistance-switching characteristics in single compounds has been long inspired scientific and technological interests. Here, we report the non-volatile resistance change in noncentrosymmetric compounds investigated by using defect nanotechnology and contact engineering. Using a noncentrosymmetric material of ZnO as example, we first transformed ZnO into high res...

It has been known for over twenty years that rhombohedral c-germanium telluride is predicted to be a narrow gap semiconductor. However, it always displays p-type metallic conduction. This behaviour is also observed in other chalcogenide materials, including Ge2Sb2Te5, commonly used for optically and electrically switched, non-volatile memory, and so is of great interest. We present a theoretica...