Polyimide–Organosilicate Hybrids with Improved Thermal and Optical Properties

Through hydrolysis and polycondensation of amino-silane with alkyl bridged silane, a new type of polysilsesquioxane (PSSQ) was obtained. Here we use amine functionalized silane and bis­(silyl)­ethane to synthesize alkyl chain linked PSSQ. Compared to conventional polyhedral oligomeric silsesquioxane (POSS), this new silane compound has both enhanced thermal stability and improved compatibility with poly­(amic acid). Gelation of this silane compound with poly­(amic acid) provides polyimide–organosilicate composite materials. We show that films made from solutions of the composites exhibit higher optical transparency and superior dimensional stability during thermal treatment than films of pure polyimide or of polyimide composites with conventional POSS. Bridging of POSS and chemical bonding between POSS and polyimide chains significantly enhance the physical properties. These results provide useful information for designing molecular architecture for the fabrication of high-performance plastic substrates in the future display devices

Controlled Charge Trapping and Retention in Large-Area Monodisperse Protein Metal-Nanoparticle Conjugates

Here, we report on charge-retention transistors based on novel protein-mediated Au nanoparticle (NP) arrays, with precise control over dimension and distribution. Individual NPs are coated with alpha-synuclein, an amyloidogenic protein responsible for Lewy body formation in Parkinson’s disease. Subsequently, a monolayer of protein-NP conjugates is successfully created via a simple and scalable solution deposition to function as distributed nanoscale capacitors. Controllability over the film structure translates into the tunability of the electrical performance; pentacene-based organic transistors feature widely varying programmability and relaxation dynamics, providing versatility for various unconventional memory applications

Low-Voltage Flexible Organic Electronics Based on High-Performance Sol–Gel Titanium Dioxide Dielectric

In this letter, we report that high-performance insulating films can be generated by judicious control over the microstructure of sol–gel-processed titanium dioxide (TiO₂) films, typically known as wide-bandgap semiconductors. The resultant device made of 23 nm-thick TiO₂ dielectric layer exhibits a low leakage current density of ∼1 × 10^–7 A cm^–2 at 2 V and a large areal capacitance of 560 nF cm^–2 with the corresponding dielectric constant of 27. Finally, low-voltage flexible organic thin-film transistors were successfully demonstrated by incorporating this versatile solution-processed oxide dielectric material into pentacene transistors on polyimide substrates