Search

Ion implantation is an interesting method to dope semiconducting materials such as zinc oxide provided that the implantation-induced defects can be subsequently removed. Nitrogen implantation followed by anneals under O2 were carried out on zinc oxide nanowires in the same conditions as in a previous study on bulk ZnO [Perillat-Merceroz et al., J. Appl. Phys. 109, 023513 (2011)], allowing a direct comparison of the defect recovery mechanisms. Transmission electron microscopy and cathodoluminescence were carried out to assess the effects of nitrogen implantation and of subsequent anneals on the structural and optical properties of ZnO nanowires. Defect recovery is shown to be more effective in nanowires compared with bulk material due to the proximity of free surfaces. Nevertheless, the optical emission of implanted and annealed nanowires deteriorated compared to as-grown nanowires, as also observed for unimplanted and annealed nanowires. This is tentatively attributed to the dissociation of excitons in the space charge region induced by O2 adsorption on the nanowire surface. [ABSTRACT FROM AUTHOR]

We have examined the crystallographic structure of GaAs/InP interfaces obtained by wafer fusion following different procedures. Plan-view and cross-sectional transmission electron microscopy reveal that the interface is not only composed of a regular array of two sets of edge dislocations and is more complex than generally supposed. If a twist is created due to misalignment of the two substrates, the dislocations are not edge dislocations but also have a screw component. Dislocations for which the Burgers vectors have a component normal to the interface are also present. Those dislocations probably result from steps and some of them accommodate the tilt between the two substrates. Inclusions and voids as well as a low number of volume dislocations are present in all the samples. The observed volume dislocation density near the interface lies in the 10[sup 5]–10[sup 7] cm[sup -2] range and these volume dislocations may be associated with thermal mismatch. The origin of all these defects is discussed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study which examined implantation-enhanced interdiffusion of CdTe-ZnTe strained heterostructures using photoluminescence channeling, transmission electron microscopy and secondary-ion-mass spectrometry. Details on studies of implantation-enhanced interdiffusion of semiconductor interfaces; Experimental conditions and samples; Implantation in bulk materials and heterostructures.

Copyright of Journal of Microscopy is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pure Fe-Cr alloys (1 and 3 wt% Cr) were gas nitrided (NH3, N2, N2O mixture at 823 K). Two modes of CrN precipitation: continuous (fine disc-shaped precipitates) and discontinuous (lamellae-like precipitates) were identified and investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Both types of precipitates presented a cubic NaCI-type structure and Baker-Nutting orientation relationship with respect to the ferritic matrix. A quantification procedure based on TEM images exploitation revealed that the size and the number of the fine precipitates vary inversely with nitriding depth. This result was compared to the profile of micro-hardness. SEM observations showed that only superficial regions in the Fe-3 wt% Cr were transformed by the discontinuous precipitation of CrN. Electron back-scattered diffraction (EBSD) studies of lamella revealed singular initiation and growth features. A qualitative mechanism of lamella initiation and growth is discussed. [ABSTRACT FROM AUTHOR]