Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

The industrial electrolytic processes to produce, aluminum, cooper, zinc, nickel, manganese, silicon carbide, chlorine and its derivative, require current values which greatly exceed the capability of single rectifying devices and paralleled combinations of semiconductors or equi...

A brief overview of electron manipulations in nanostructured semiconductors is given. Such manipulations go average transfer of less than a single electron per controlled step. The applications to nanodevices the scaled down silicon microelectronics is also discussed....

The large dielectric constant and small effective mass in a semiconductor allows a description of its electronic states in terms of envelope wavefunctions whose energy, time, and length scales are mesoscopic, i.e., halfway between those of atomic and those of condensed matter sys...

A short overview is given of recent advances in the field of carrier-controlled ferromagnetism in Mn-based III-V and II-VI diluted magnetic semiconductors and their nanostructures. The tailoring of domain structures and magnetic anisotropy by strain engineering and confinement is...

Orientador: José Antônio Brum...

Nucho et al (Phys. Ver. B17, 1843 e 4835 (1978)) developed the chemical-bond approach to calculate the dielectric constant of tetrahedral semiconductors. They expressed e 1 (0), via Kramers-Kroing relations, as a function of the zeroth and first order moments of e 2 (w ) and negl...

The solar-to-chemical energy conversion is promising to tackle sustainability challenges toward a global future. The production of H2 from sunlight represents an attractive alternative to the use of carboniferous fossil fuels to meet our energy demands. In this context, the water...

It is presented a simple model for the calculation of the transition rate for impurities in semiconductors in which electron-phonon interaction is taken into account in a second order time dependent perturbation theory. This result shows the explicit dependence of the transition ...

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Mercuric iodide "alfa"-"HgI IND.2 in its red tetragonal crystalline phase is a semiconducting material of great technological interest due to the potential applications as a detector for y- and X-ray spectroscopy to be operated at room temperatures....

The nowadays notable development of all the modern technology, fundamental for the progress and well being of world society, imposes a great deal of stress in the realm of basic Physics, more precisely on Thermo-Mechanical Statistics. In electronics and optoelectronics we face si...

In Brazil, the sector of semiconductors components, the chips, remains restricted to a small group of companies, fact that has caused deficit increasing in the trade balance. Ahead of this fact, there are several discussions and studies in forms to increase the internal productio...

Heterostructured semiconductors are materials with unique features formed by combination of two or more semiconductors with suitable interface between them. The study of the heterostructures aim the development of physico-chemical and photocatalytic properties higher than their i...

Advanced oxidative processes (AOPs) are based on chemical processes that can generate free radicals, such as hydroxyl radicals (.OH) which are strong, non-selective oxidant species that react with the vast majority of organic compounds. Nanostructured semiconductors, especially t...

Orientador: Maria José Santos Pompeu Brasil...

There is nowadays a growing demand for located cooling and stabilization in optical and electronic devices, haul of portable systems of cooling that they allow a larger independence in several activities. The modules of thermoelectrical cooling are bombs of heat that use efect Pe...

This work presents the study and implementation of an ac-dc Ćuk converter based on the three state switching cells applied in charger stations for electric vehicles. This converter has, as main characteristics, reduction of conducting power losses in the semiconductors, a single ...

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Along the last few years, the doping of semiconductors (either II-VI, IV-VI, III-V, and group-IV compounds) with magnetic species have been extensively studied due to their potential applications in spintronics. Among them, Si- and Ge-based magnetic semiconductors are very attrac...

Organic semiconductors based on π-conjugated oligomers and polymers constitute the active elements in new generations of plastic (opto)electronic devices. The performance of these devices depends largely on the efficiency of the charge-transport processes; at the microscopic leve...