摘要:

A new model for the formation of metastable Staebler–Wronski (SW) defects in a-Si: H is proposed. The phonons of local Si–H vibrational modes released in the non-radiative recombination of photoexcited electrons and holes through weak Si–H bonds may break the Si–H bonds themselves and result in an increase of Si dangling bonds, that is, SW defects. The model provides a reasonable qualitative explanation of all the important experimental results related to the phenomenon.

ISSN:0950-0839    

DOI:10.1080/09500838808229620

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Nuclear reaction analysis has been used to measure deuterium content in SiO2thin films (224–230 nm) grown in dry oxygen and treated in D2O steam at 700–930°C and 0·22–16 mbar. The deuterium profiles are nearly flat. It is argued that the deuterium is predominantly in the form of Si–OD. The OD concentration does not vary as the square root of the steam pressure, as expected, and saturates above ∼ 7 mbar. This is interpreted in terms of a decrease in the reactivity between water and silica with increasing pressure. We discuss the latter point.

ISSN:0950-0839    

DOI:10.1080/09500838808229621

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The exact solution of theq-state Potts bridge model with competing ferromagnetic and antiferromagnetic interactions is obtained and corresponding regular and critical behaviour studied.

ISSN:0950-0839    

DOI:10.1080/09500838808229622

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The hole drift mobility in a-Si:H p-i-n junction specimens has been investigated between 250 and 455 K. It is shown that effects associated with anomalous dispersion disappear above 360 K. In the range between 360 and 455 K results have been fitted to the multi-trapping transport model, making it possible to deduce the extended-state hole mobility μv. Assuming a temperature dependence of the form μv∞T−n(withn=0·5 and 1·0), analysis of the data leads to μvvalues between 0·4 and 0·8 cm2V−1s−1at 295 K.

ISSN:0950-0839    

DOI:10.1080/09500838808229623

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The sp2sites present in the various forms of amorphous carbon have been shown to form aromatic clusters whose size determines the width of the local band gap. A fluctuating band-edge model is developed to describe the effects of this clustering on the localization of states around the gap. It is shown how localized states exist at energies well above the optical gap of a-C:H.

ISSN:0950-0839    

DOI:10.1080/09500838808229624

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Superconducting and mechanical properties of Y1Ba2Cu3O7can be improved by the use of sintering aids. 0·2 wt% of finely divided laser-ablated platinum powder has been mixed with the parent material and produced a dense product with exaggerated grain growth and improved critical current density and Vickers hardness. At higher concentrations of platinum, while the mechanical properties are further improved, the increased density appeared to inhibit access of oxygen for the tetragonal to orthorhombic phase transition and the current density was reduced.

ISSN:0950-0839    

DOI:10.1080/09500838808229625

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0950-0839    

DOI:10.1080/09500838808229626

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor