Title: Processing Organic Semiconductors in Electric-Fields for Morphology Control in Organic Electronic Devices
Speaker: Sumit Chaudhary, Associate Professor
Abstract: In organic semiconductor based devices, morphologies at molecular, meso and micro scales directly impact the device performance. For instance, phase separation in blends governs the efficiency of exciton dissociation and charge transport in organic photovoltaics, intra and interchain interactions govern the emission spectra and efficiency in light-emitting-diodes, and chain packing affects charge transport in these devices as well as thin-film transistors. Typical morphological control techniques, such as annealing and varying solvent compositions, are material specific and isotropic. In this talk, we present a new technique for controlling morphology in polymeric films– exposing these films to electric-field as the films solidify from wet state. Our preliminary experimental investigations show that owing to intrinsic charge-carrier density in these systems, electric-field notably affects the morphology, effects are on multiple length scales, and depend on the direction of electric-field. We will discuss our results and discuss their technological impact across various organic electronic devices.