In today’s modern world, energy claims itself to be an undying asset of every nation. Fossil fuels like crude oil, coal, and natural gas have been used since time immemorial to generate various forms of energy including electricity. With growing fears of conventional fuels becoming extinct with time, all communities around the globe are working to discover alternatives for the conventional fuels that also promise the best ecosystem for future generations. Thus, the research for better energy harvesting and storage devices is at its apex
Photovoltaic (PV) technology has seen an unprecedented growth in recent years. The most commonly used PV materials are monocrystaline and polycrystalline silicon, cadmium telluride, and copper indium gallium selenide. Currently, these solar cells have the capability of reaching efficiency up to 45% (NREL Cell Efficiencies, 2012). However, as they are expensive to mass-produce and require energy for manufacturing, the demand for flexible, cheaper, mass-producible, and lightweight solar cells is high in the scientific community. Augmenting this demand, the conferring of Nobel Prize in Chemistry for the year 2000 to Dr. Alan Heeger in recognition of his work on conducting polymers has decisively paved a new era for organic electronics, organic photovoltaics (OPV), and organic/flexible displays (Shirakawa, Louis, MacDiarmid, Chiang, & Heeger, 1977).
An Organic Solar Cell (OSC) or plastic solar cell is an evolving multidisciplinary area of research that involves theoretical, experimental, and design challenges dealing with carbon based materials and other organic compounds. It is a brand of polymer solar cell which incorporates conductive organic polymer for light absorption, exciton dissociation, and charge transport to generate electricity (Mayer, Scully, Hardin, Rowell, & Mcgehee, 2007). It is different from the conventional silicon and other inorganic material based cells as they are cheaper (Kalowekamo & Baker, 2009) and can also be fabricated via low cost solution processing techniques like spin coating, brush painting, and spray coating. These solution-processing techniques fetch desired thicknesses of a few hundred nanometers and sober efficiencies of 4-5%. The wide multi-polymer layered architectures of organic solar cells help execute the process of photon trapping, the generation of electrons and holes, and the transport of charges to the respective cathodes and anodes. Recently, both Mitsubishi Electronics and the University of California Los Angeles have claimed the highest efficiency of 10% for organic solar cells (Kobayashi, 2011; Yang, 2012). The first organic solar cell was invented by C. W. Tang in the mid-1980s with 1% efficiency and was based on a two-layered donor and acceptor materials (Tang, 1986). The two different organic materials sandwiched between the two electrodes work as a photovoltaic device. Since it speaks loud about flexible energy, need for 4 MRS symposia (A,B,C,D) is well justified.