Plasma-modified interlayers applied to processing of polymer electronic materials

Summary form only given. Intrinsic conducting polymer (ICP) is a new class of material. Fabrication of devices from ICP is a rapidly growing industry that has the potential to facilitate major changes in products such as flexible displays, RFID tags, sensors, smart packaging, electronic paper, membrane keyboards, smart fabrics (electronic textiles), and solar cells. Low-cost, high-speed, high-resolution ink jet printing will expedite the marketing of polymer electronics fabricated from ICP inks. Two issues associated with polymer electronic inks are: 1) the materials are new and little is known regarding their electrical properties and 2) wettability of the previously deposited dry polymer layer has a major influence on the coverage and adhesion properties of the liquid polymer being printed to the surface. Surface wettability is characterized by terms such as hydrophilic, hydrophobic, contact angle, surface tension, and surface energy. Many ICPs are classified by polypyrrole, polythiophene, polyaniline and their derivatives. The most important feature in ICPs is the presence of pi-conjugated molecules. Plasma-processed interlayers are known to effectively control wettability and other properties of polymer surfaces. Plasma will be used to etch the existing dry polymer electronic surface before the subsequent layer of polymer electronic material is deposited in the liquid phase. Plasma-polymerization will also be used to deposit interlayers during these processing steps. Influence of plasma-processed interlayers on electrical properties of sandwich structures will be measured. The HP4145B transistor parameter analyzer and the HP4192LF impedance analyzer will be used. The former will measure current-voltage (IV) characteristics while the latter will measure impedance spectra. From IV data, emission and conduction phenomena such as Schottky current, Poole-Frenkel conduction, field emission, space-charge-limited emissions, ohmic conduction, and percolation can be identified. From impedance spectra, AC permittivity and AC conductivity will be measured as functions of frequency. Impedance spectra can also identify phenomenon such as conduction via hopping. Recent experimental results will be presented