Organic electronics is a relatively young and active field, focusing on developing novel technologies based on molecular organic semiconductors, instead of traditional inorganic materials like Si, Ge or GaAs. Organic materials are, in many aspects, beneficial and superior to their inorganic counterparts. For example, versatility of chemical synthesis allows synthesis of hundreds of new molecules with different physical properties (e.g., varied HOMO-LUMO gap); organic semiconductors in many cases allow inexpensive low-temperature fabrication techniques, including solution processing, painting and evaporation; it is relatively easy to create flexible organic electronic devices; organic semiconductors are active in the visible part of the spectrum which makes them promising for photovoltaic and other opto-electronic applications.
This talk will introduce some aspects of organic electronics, and will focus more on organic photovoltaics and the fundamental problems of exciton generation, transport and dissociation in organic solar cells. In particular, single-crystal organic devices, developed by us at Rutgers, are very useful in studying the intrinsic (that is, not dominated by static disorder) properties of organic semiconductors. For instance, I will show that in high-purity molecular crystals, singlet-triplet and triplet-singlet conversion processes (fission and fusion) and long-range (3-8 micrometers) triplet exciton diffusion might be prominent phenomena that will be important for design and operation of organic photo-voltaic and photo-conductive devices.