On interaction of low-energy particles with a-Si:H and a-SiGe:H thin films

A chapter on the interaction of low-energy particles with a-Si:H and a-SiGe:H thin film

On structural properties of a-Si based semiconductors

A chapter on structural properties of a-Si based semiconductor

Transformation of semiconductor surfaces due to low-energy particle impacts

This paper looks at the transformation of semiconductor surfaces due to low-energy particle impact

Photoluminescence, structural and electrical properties of passivated a-Si:H based thin films and corresponding solar cells

This paper deals with the photoluminescence, structural and electricalproperties of chemically passivated a-Si:H basedthinfilms and correspondingthinfilmsolarcells. The structures were chemically passivated in three types of KCN and HCN solutions containing MeOH and/or with water. The photoluminescence measurements were performed at 6 K using Ar laser and lock-in signal recording device containing Ge and Si photodetectors. Optically determined band gap related photoluminescence signals were observed between 1.1 and 1.7 eV. The electricalproperties were measured by a high-sensitive charge version of deep level transient spectroscopy (Q-DLTS). The evolution of three basic groups of defects was observed. The structural studies were realized by the standard X-ray diffraction analysis. The cyanide treatment improved significantly the electrical characteristics of both corresponding MOS structures and solarcells due to the passivation of some parts of the dangling bonds by CN group. Particularly, the passivation of the defects at interfaces in MOS or solarcell multilayer structures was achieved which is of primary practical importance

Properties of semiconductor surfaces covered with very thin insulating overlayers prepared by impacts of low-energy particles

This paper deals with the formation of very thin insulating layers on crystalline (GaAs) and amorphous semiconductors (a-Si:H and a-SiGe:H) prepared by the impacts of particles of a very low energy. Plasma, ion beams and plasma immersion ion implantation (PIII) as the sources of impacting particles were used and compared. The last technique was applied successfully for the first time in the case of amorphous silicon-based semiconductors. More diagnostics techniques were used for the investigation of the transformation of the semiconductor surface properties. In the a-Si:H based MOS structures prepared by PIII technology, only two groups of defects 0.82 and 1.25 eV (D(z) and D(e), respectively) were found. We suppose that the PIII technology using the implantation at the sample voltage of ca. -1000V causes the formation of a-Si:H layers with missing group of D(h) states. The only decisive parameter determining the formation of two groups of states is the negative potential of the sample during the implantation. In aSiGe:H based MOS structures, three distributions could be prepared by a bias annealing procedure: 0.47, 0.58 and 0.95 eV corresponding to p-type (D(h)) intrinsic (D(z)) and n-type (D(e)) distributions, respectively

Comparison of monoamine concentrations in the brains of adult male and female Japanese quail.

A fluorometric assay measuring brain tissue concentrations of norepinephrine, dopamine, and serotonin has been validated for Japanese quail. Accuracy, precision, specificity, and parallelism were determined. The sensitivity of the assays was 6 ng/tube, which allowed individual assay of 1 to 2 mg hypothalamic tissue. In Experiment 1, relatively large areas of brain from adult, reproductively active males and females were found to differ significantly in norepinephrine content in optic lobes and for dopamine in right telencephalon. A microdissection technique was used in Experiment 2 to sample small portions of hypothalamic tissue. Sex differences were observed for norepinephrine in the sections containing the lobus paraolfactorius and the preoptic, anterior, and medial hypothalamus. Differences in monoamine content were most apparent when smaller areas dissected by microdissection were analyzed. These results give evidence for sex differences in the monoamine content in specific areas of the brain