Date : 2011. 6. 2, 5:00 PM Place : Mogam Hall, Bldg.500 -Abstract-    Organic electronics such as organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs) have attracted a great deal of attention for the last two decades due to their cheap and easy fabrications, potential for the flexible and large-area devices, etc and remarkable achievements have been established; in the case of OLEDs, full color displays have already emerged in the market, and for OPVs, it was recently reported that devices with 8 % power conversion efficiency has been realized. However, for these electronics of new paradigm to be more competitive compared to conventional ones, there still must be further major improvements which can be accomplished only via better understandings of various physicochemical phenomena in the device operation and a well-refined design of chemicals based upon them.    In this talk, after some brief introduction of organics electronics, I will present results of recent theoretical studies which includes; i) electronic properties of low-band gap polymers; ii) morphology of p-conjugated polymers and polymer:fullerene blends; iii) excimer formation of light-emitting phosphors in OLEDs; iv) structure-property relationships of the host materials for blue OLEDs.