The modification of Si nanocrystallites embedded in a dielectric matrix by high energy ion irradiation
We have followed the effects of heavy ion irradiation on the structural, electrical, and photoluminescence properties of ensembles of silicon nanocrystallites embedded in a dielectric (SiO2) matrix. This was done as a function of the irradiation dose and the content of the Si phase. The results obtained can be accounted for self-consistently assuming that a relatively small dose of the irradiation enhances the crystallization while for higher doses the irradiation enhances the amorphization. The corresponding processes suggest that tuning of the above properties can be achieved by swift heavy ion irradiation.
Silicon amorphization during ion implantation as a thermal phenomenon.
A model to understand the amorphization mechanism during ion implantation in silicon is proposed. This model ascribes the amorphization to single-recoil events, each in itself able to transfer to the lattice the energy necessary to amorphize it. The threshold energy required by this process depends in principle on the considered lattice and can be estimated with simple considerations. The proposed model is quantitatively tested by considering the implant of boron into (100) silicon, though it can be easily extended to other ions and crystal orientations. The model accounts for superlinear damage release often observed for increasing fluence and for superadditive effects occurring when collisional cascades superimpose on one another.
Immersive haptic interaction with media
New 3D video representations enable new modalities of interaction, such as haptic interaction, with 2D and 3D video for truly immersive media applications. Haptic interaction with video includes haptic structure and haptic motion for new immersive experiences. It is possible to compute haptic structure signals from 3D scene geometry or depth information. This paper introduces the concept of haptic motion, as well as new methods to compute haptic structure and motion signals for 2D video-plus-depth representation. The resulting haptic signals can be rendered using a haptic cursor attached to a 2D or 3D video display.