Organic thin film transistors on back molded plastic foil

Abstract

Organic thin film transistors, unipolar inverters and ring oscillators have been fabricated on plastic foil and afterwards embedded into a plastic substrate by using an injection molding process. The transistors have an effective field-effect mobility of 0.001 cm 2 V −1 s -1 , an on/off ratio of 10 5 and threshold voltage V th of 0.5 V while the inverter shows a gain of 1.6 at V dd =−10 V. The five-stage ring oscillator showed an oscillation frequency of ∼11 Hz at V dd =−10 V. The results demonstrate the transfer of organic electronic devices fabricated on plastic foil onto the surface of a 3D plastic object by using injection molding process, one of the most common modern methods of part manufacturing.

F-Center-Mediated Growth of Patterned Organic Semiconductor Films on Alkali Halides

“…However, device processing also requires lateral structuring and patterning of the semiconducting films, which remains challenging for molecular materials since photolithography is not applicable due to the radiation sensitivity and lack of chemical robustness in the etching process of these materials, causing their degradation . Therefore, alternative approaches are necessary, which are based on a spatially selective deposition (using shadow masks, inkjet or gravure printing − ), controlled nucleation on pre-structured substrates (using inorganic surface patterns or printed self-assembled monolayers), or subsequent removal of material (by means of molding, laser ablation, or nanoscratching). In addition, control of the molecular aggregation and patterning of films by laser illumination during the deposition was also demonstrated, which is caused either by local heating of the substrate surface or by suppression of specific domains due to orientation-selective optothermal heating .…”