Metastable phase control of two-dimensional transition metal dichalcogenides on metal substrates

Engineering the stability of the metastable phase of 2D MoS2 by appropriate choice of metal substrate determined by the electron occupation of Mo d-orbitals.

High electron mobility of β-HgS colloidal quantum dots with doubly occupied quantum states

Steady-state electron occupation of the lowest quantum state in the conduction band of a colloidal quantum dot gives rise to unique electrical properties. An electron mobility of 1.29 cm2 V−1 s−1 was measured in a mercury sulfide quantum dot FET.

Quantum capacitance as a reagentless molecular sensing element

The application of nanoscale capacitance as a transduction of molecular recognition relevant to molecular diagnostics is demonstrated, wherein the energy-related signal relates directly to the electron occupation of quantized states.

Sodium Interaction with Disodium Terephthalate Molecule: an Ab Initio Study

ABSTRACTDisodium terephthalate (Na2TP), which is a disodium salt of terephthalic acid, is very promising organic electrode material for Na-ion batteries. We present an ab initio study of Na binding mechanism with Na2TP molecule. Specially, we provide the interaction energy of Na atom(s), effect of Na concentration on interaction energy, electronic properties of clean and Na attached Na2TP, and Na binding mechanism with Na2TP. We show that up to eight Na atoms can be attached to a single Na2TP molecule. The interaction energy of Na atoms varies from -0.79 to -0.66 eV with attachment of one to eight Na atoms. The adsorbed Na atom interacts with O atoms of carboxylate group and Na atoms of the salt molecule. The interaction between adsorbed Na and C atoms of the molecule is found to be not important for Na bindings. Attachment of a single Na atom generates a singly occupied orbital which becomes doubly occupied with attachment of second Na atoms. Attachment of more than two Na atoms leads to electron occupation of bonding orbitals formed between Na atoms and the carboxylate groups.

Tailoring the Surface Reactivity: Comparison of Pd/Nb(110) and Rh/Nb(110)

Ni, Pd and Pt overlayers deposited on many metallic surfaces show properties resembling those of noble metals. We pose the question whether a similar trend might occur also for other transition-metal overlayers. To this goal, we perform first-principles density-functional theory calculations for Pd(111), Rh(111) surfaces, Pd and Rh epitaxial monolayers deposited on Nb(110), and for CO chemisorption on these systems. Density functional calculations indicate that the behavior of the two overlayers is quite different. Whereas the Rh overlayer on Nb(110) resembles the Rh(111) surface, for the Pd overlayer the electronic structure around the Fermi level is strongly affected by hybridization with Nb electrons, which accounts for unique properties of the overlayer. We expect that the latter mechanism may be of importance just for Pd, Pt, Ni and not for other transition metals with lower d-electron occupation.

Hydrogen-Related Donors in Silicon: Centers with Negative Electronic Correlation Energy

The transformation of the shallow hydrogen-related donors, which have been formed in the silicon samples by irradiation of the low energy (300 keV) protons and following heat treatment under 350 0С or 450 0С was investigated. The experiment was carried out on Ag-Mo-Si Shottky diodes and diodes with shallow p+-n-junction. The concentration and distribution of these donors were defined by C-V-method at 1.2 MHz frequency. Using temperature dependence of equilibrium electron concentration it was established, that the hydrogen-related donors were charged controlled centers with negative electronic correlation energy (U<0). The transformation between both equilibrium configurations of the double hydrogen-related donor takes place when value of the Fermi level is arranged near Ec-0.30 eV. It was revealed that the donor transformation from neutral into double charged state have been stimulated by minority carriers trapping under room temperature when Fermi level was higher then level of the double electron occupation E(0/++)= Ec-0.30 eV.