Enhancing the performance of solution-processed n-type organic field-effect transistors by blending with molecular "aligners".

A novel approach to enhancing the performance of solution-processed n-type organic field-effect transistors by using trace amounts of molecular "aligners" to manipulate the assembly of "matrix" molecules in thin films is demonstrated. The device performance is one order of magnitude higher in 1wt% blended thin films than that in neat films, which correlates to an induced change of preferred orientation of the in-plane π-stacking molecules upon blending.

PbS nanoparticles capped with tetrathiafulvalenetetracarboxylate: utilizing energy level alignment for efficient carrier transport.

We fabricate a field-effect transistor by covalently functionalizing PbS nanoparticles with tetrathiafulvalenetetracarboxylate. Following experimental results from cyclic voltammetry and ambient-pressure X-ray photoelectron spectroscopy, we postulate a near-resonant alignment of the PbS 1Sh state and the organic HOMO, which is confirmed by atomistic calculations. Considering the large width of interparticle spacing, we observe an abnormally high field-effect hole mobility, which we attribute to the postulated resonance.

High aspect ratio sub-15 nm silicon trenches from block copolymer templates.

High-aspect-ratio sub-15-nm silicon trenches are fabricated directly from plasma etching of a block copolymer mask. A novel method that combines a block copolymer reconstruction process and reactive ion etching is used to make the polymer mask. Silicon trenches are characterized by various methods and used as a master for subsequent imprinting of different materials.