The dynamic process of the reactions during deposition of M(Hf or Zr)O2 thin films on SiO2-covered silicon substrate in oxygen deficient conditions has been investigated. A series of reactions across the interface were identified with thermodynamic arguments and with X-ray Photoelectron Spectroscopy (XPS) and transmission electron microscopy (TEM) analyses. The oxygen deficient MOx < 2 absorbs ...

We theoretically elucidate the origin of unintentional doping in two-dimensional transition-metal dichalcogenides (TMDs), which has been consistently reported by experiment, but which still remains unclear. Our explanation is based on the charge transfer between TMDs and the underlying SiO2 in which hydrogen impurities with a negative-U property pin the Fermi level of the SiO2 as well as adjace...

Nanoencapsulated phase change materials (NePCMs) are promising thermal energy storage (TES) and heat transfer that show great potential in battery management systems (BTMSs). In this work, nanocapsules with a paraffin core silica shell were prepared using an optimized sol-gel method. The samples characterized by different methods regarding chemical composition, properties, etc. Then, the used a...

The breakthrough of 4H-SiC MOSFETs is stemmed mainly due to the mobility degradation in their channel in spite of the good physical intrinsic material properties. Here, two different n-channel 4H-SiC MOSFETs are characterized in order to analyze the elemental composition at the SiC/SiO2 interface and its relationship to their electrical properties. Elemental distribution analyses performed by E...

Two heterogeneous catalysts, MNP@SiO2-N-Xantphos/Rh(I) and MNP@SiO2-NH-C-scorpionate/Fe(II), were prepared by reaction of chloro-functionalized MNP@SiO2 with N-Xantphos amino-functionalized iron(II)/C-allyl-scorpionate through nucleophilic substitution hydroaminomethylation reactions, respectively. All catalysts characterized using standard spectroscopic means, transmission electron microscopy ...

Gates can electrostatically control charges inside two-dimensional materials. However, integrating independent gates typically requires depositing and patterning suitable insulators and conductors. Moreover, after manufacturing, gates are unchangeable. Here we introduce tunnelling triboelectrification for localizing electric charges in very close proximity of two-dimensional materials. As repre...

As one of the most prominent anticake agent, SiO2 nanoparticle synthesis method was modified and investigated for a better understanding fabrication process. Hence, tetraethoxysilane presursor subjected to varying procedures such as concentration change surface modification ligants. pH value all other material composition kept same by implying sol-gel reaction mechanism, basic catalysis tempera...

The Pd-catalyzed hydrogenation of anthraquinone to synthesize hydrogen peroxide is an important process in the chemical industry. A Pd catalyst with high dispersion key activity and selectivity. For first time, this team introduced AlPO-5 zeolite SiO2 powder prepare a finely dispersed higher efficiency than conventional Pd/SiO2 catalyst. Based on previous research, other aluminophosphate molecu...

and Introduction: There are currently no electrically-pumped semiconductor lasers that can operate in the 1-5 terahertz (THz) spectral range at room temperature. An alternative method of producing room temperature THz light is based on intra-cavity difference frequency generation (DFG) in dual wavelength mid-infrared quantum cascade lasers. Our THz DFG sources can provide tunable output of over...

First-principles calculations show that the electronic structure of graphene on SiO2 strongly depends on the surface polarity and interface geometry. Surface dangling bonds mediate the coupling to graphene and can induce hole or electron doping via charge transfer even in the absence of extrinsic impurities in substrate. In an interface geometry where graphene is weakly bonded to an O-polar sur...