This letter demonstrates the use of a traditional screen printing approach for the fabrication of silicon field effect transistors. Using purely additive patterning technologies at room temperature conditions, with no additional postprocessing steps, transistors have been produced on paper substrates that have performance characteristics comparable to amorphous silicon thin film transistors. Insulated gate field effect transistors employing n type silicon in the semiconductor layer operate in accumulation mode with effective carrier mobilities in the range 0.3 to 0.7 cm2 (V s)−1.

The mechanical properties of mesoporous silica films were characterized by x-ray reflectivity measurements. The measurements provide information on the deformation of the pores and the walls induced by the adsorption of water in the pores. The analysis of the nanoscaled deformations supplies a method to determine the elastic modulus E of thin porous films. The nanodeformation of the porous network during its filling with water is interpreted in three regimes of isotherm sorptions.

Nanomaterials with disordered, ramified structure are increasingly being used for applications where low cost and enhanced performance are desired. A particular example is the use in printed electronics of inorganic conducting and semiconducting nanoparticles. The electrical, as well as other physical properties depend on the arrangement and connectivity of the particles in such aggregate systems. Quantification of aggregate structure and development of structure/property relationships is difficult and progress in the application of these materials in electronics has mainly been empirical. In this paper, a scaling model is used to parameterize the structure of printed electronic layers. This model has chiefly been applied to polymers but surprisingly it shows applicability to these nanolayers. Disordered structures of silicon nanoparticles forming aggregates are investigated using small angle x-ray scattering coupled with the scaling model. It is expected that predictions using these structural parameters can be made for electrical properties. The approach may have wide use in understanding and designing nano-aggregates for electronic devices.

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A pLlseo low-energy positron system for posaron-l.le1ime spectroscopy has been Jp-graded and modified with regard to .IS tnree ma'n components. A new moderator preparation chamber has been added, the radiofrequency pLlsing concepl has been modified using a pre-buncher and a pre-chopper in front of the ex:sling chopper-ouncher section. Furthermore, a new target station allowing measurements at variable temperarures has been incorporated. The l.felime speclra now reveal a strongly increased rat.0 of pea6 to background and of peak to sarell're peak