Sequential Doping Reveals the Importance of Amorphous Chain Rigidity in Charge Transport of Semi-Crystalline Polymers.

Sequential doping is a promising new doping technique for semicrystalline polymers that has been shown to produce doped films with higher conductivity and more uniform morphology than conventional doping processes, and where the dopant placement in the film can be controlled. As a relatively new technique, however, much work is needed to understand the resulting polymer-dopant interactions upon sequential doping. A combination of infrared spectroscopy and theoretical simulations shows that the dopants selectively placed in the amorphous regions in the film via sequential doping result in highly localized polarons.

Bandgap Restructuring of the Layered Semiconductor Gallium Telluride in Air.

A giant bandgap reduction in layered GaTe is demonstrated. Chemisorption of oxygen to the Te-terminated surfaces produces significant restructuring of the conduction band resulting in a bandgap below 0.8 eV, compared to 1.

Strain effects on the work function of an organic semiconductor.

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction.