For certain dopants, luminescence measurements allow one to distinguish between single-ion and pair-state dopant emission in a (semiconductor) host. In a bulk crystal the concentration of each of these dopant-states can be calculated from the dopant fraction f present in the material, and is found to correlate with luminescence measurements. However, for a nanocrystalline host-lattice, these co...

Using density functional theory (DFT) based electronic structure calculations, the effects of morphology of semiconducting nanostructures on the magnetic interaction between two magnetic dopant atoms as well as a possibility of tuning band gaps have been studied in the case of the bi-doped (ZnO)24 nanostructures with the impurity dopant atoms of the 3d late transition metals-Mn, Fe, Co, Ni, and...

Structural and electronic properties of pure In2O3 and its alloys with Sc, Y, La and Ac including the band gap, the effective mass and the effect of dopant ionic radius have been investigated using density functional theory (DFT). The full potential linearized augmented plane wave (FL-LAPW) method was used with the local density approximation (LDA+U). The calculated results indicated that, subs...

Annealing or growth at high temperatures for an extended period of time is considered detrimental for most synthetic strategies for high-quality Mn-doped II-VI semiconductor nanocrystals. It can lead to the broadening of size distribution and, more importantly, to the loss of dopants. Here, we examine how ripening can be beneficial to doping in a simple "heat-up" approach, where high dopant con...

Conductive polymers are a new class of materials, which exhibit highly reversible redox behavior and unusual combination of properties of metals and plastics. The conductivity of a polymer can be increased several-fold by doping it with a suitable dopant. Doping plays a very important role to convert the polymer into conductive form. In this work an attempt has been made to synthesize polyanili...

The present study is devoted to the problem of enhancing fracture toughness of ZrO2 ceramic materials through the formation of composite structure by addition of Al2O3 and NiO particles. In this paper, we analyzed the general and distinguished features of microstructure of both composite materials and its effect on fracture toughness of materials. In this paper, we used the XRD, SEM, and EDS me...

Cation segregation on perovskite oxide surfaces affects vastly the oxygen reduction activity and stability of solid oxide fuel cell (SOFC) cathodes. A unified theory that explains the physical origins of this phenomenon is therefore needed for designing cathode materials with optimal surface chemistry. We quantitatively assessed the elastic and electrostatic interactions of the dopant with the ...

Following the rapid development of the electronics industry and technology, it is expected that future electronic devices will operate based on functional units at the level of electrically active molecules or even atoms. One pathway to observe and characterize such fundamental operation is to focus on identifying isolated or coupled dopants in nanoscale silicon transistors, the building blocks...

We compare characteristics of electron impact ionization (EI) and multiphoton ionization (MPI) of doped superfluid helium droplets using the same droplet source. Selected dopant ion fragments from the two ionization schemes demonstrate different dependence on the doping pressure, which could be attributed to the different ionization mechanisms. While EI directly ionizes helium atoms in a drople...

We investigate the interaction and distribution of defects in doped non-stoichometric ceria Ce1-xRExO2-x/2-δ (with RE = Lu, Y, Gd, Sm, Nd, and La) by combining DFT+U calculations and Monte Carlo simulations. The concentrated solution of defects in ceria is described by the pair interactions of dopant ions, oxygen vacancies, and small polarons. The calculated interaction energies for polarons an...