This article presents an overview of the developments in the field of organic photovoltaics (PVs) with liquid crystals (LCs). A brief introduction to the PV and LC fields is given first, followed by application of various LCs in organic PVs. Details of LCs used in bilayer solar cells, bulk heterojunction solar cells and dye-sensitized solar cells have been given. All the liquid crystalline materials used in PVs are structured and the efficiency of solar cells is tabulated. Finally, an outlook into the future of this newly emerging, fascinating and exciting field of self-organizing supramolecular LC PV research is provided. Polymer Journal (2017) 49, 85-111; doi:10.1038/pj.2016.109; published online 9 November 2016
INTRODUCTIONFor the sustainable growth of the global economy, availability of cheap energy is essential. Our energy demand is increasing continuously to improve our lifestyle. At present, fossil energy sources are the primary sources for most of the world's current energy requirements and only a little is provided by hydropower, nuclear energy and biomass. The exponential growth of carbon dioxide level in the atmosphere owing to the burning of fossil fuels is leading to the threat of a universal climate change. Moreover, there will be limited availability of conventional energy sources in the long term. Future energy demand cannot be met with conventional sources of energy. Nuclear energy sources are one of the promising energy sources, but owing to their associated hazardousness and cost effectiveness, these energy sources does not appear to be socially acceptable universally. Moreover, nuclear fuel is also limited to tackle gigantic demand of energy. Despite several efforts, the problem of energy provision around the world remains unsolved, and there is a great need of finding alternative clean energy sources. To solve the energy crisis of the globe, exploitation of solar energy is undoubtedly the best answer. It is the most abundant inexhaustible source of regenerative energy. It is known since the evolution of life on the Earth that Mother Nature generates chemical energy from solar energy via photosynthesis. The supply of energy by Sun on Earth in an hour is more than that we use in a year. Therefore, only a fraction of solar energy is required to overcome our all energy requirements, if it can be converted to electric energy efficiently. The device that is developed to convert solar energy into electrical energy is known as photovoltaic (PV) solar cell.During the past 60 years, PV energy has been used as a promising candidate for energy devices because it is abundant, inexhaustible, cheap, straight to production ability and pollution-free that does not raise the green-house gases. The PV effect involves the generation of a photocurrent and photovoltage on absorption of light photons in a semiconductor. The three-step process, which is an
Gold nanoparticles fully covered with triphenylene-based discotic liquid crystals (DLCs) were synthesized and dispersed in a columnar matrix. The thermophysical properties of these nanocomposites, studied using polarizing optical microscopy, differential scanning calorimetry and small angle X-ray diffraction studies (SAXS), confirm their insertion into the columnar matrix. The presence of the gold nanoparticles in the triphenylene-based DLCs does not disturb the nature of the mesophase other than altering the transition temperatures. We propose that the gold nanoparticles are distributed between the domain gaps of the DLCs in random disordered manner. Interestingly the DC conductivity measurements show an enhancement of the electrical conductivity by more than a million times upon doping of the discotic liquid crystals with the triphenylene-capped nanoparticles under ambient conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.