Testing of Flexible Plastic Solar Cells on Transparent Graphene Electrodes
Solar cells that have been commercialized to date can be divided in two categories: i) high-cost, high-efficiency photovoltaics, prepared from inorganic crystalline materials and ii) low-cost, low-efficiency photovoltaics, prepared from disordered materials. Lowering the cost of solar cells at constant performances or increasing the market areas for solar cells by developing light wight or portable solar devices is vital to enhance the competitiveness of solar energy in respect of other non-renewable sources of energy and to increase increase their commercial value.
Graphene, a novel two-dimensional material made by single layer of carbon atoms, was awarded the 2010 Nobel Prize for Physics and is an excellent candidate to make solar cells cheaper. It can be used as a transparent electrode placed in front of solar devices in alternative of transparent conducting oxides that require rare chemical elements, including Indium. Another advantage of solar cells assembled on transpartent layers of graphene is that they can preserve the flexibility of graphene, while solar cells built using electrodes of transparent conducting oxides (TCOs) suffer from cracks and dislocations forming in the crystalline electrode material which lower their performance.
In this project the student will fabricate organic solar cells based on plastic semiconducting materials (including polythiophene-based polymer donors and fullerene-based polymmer acceptors) on transparent and conducting layers of graphene and compare their initial and after-bending performance with similar solar cells built on TCOs. An essential part of the project will be the characterization of the solar cell performance before and after bending tests and their correlation with the amount of defects being formed in the transparent electrode and in the solar cell active layer during bending of the device and during exposure to “harsh” atmosphere. The objective of the project is to minimize defect formation of graphene solar cells even further and to develop portable comercial solar cells modules that can be rolled or bent for transportation (e.g. in pocket or in a backpack) and unrolled for their operation (e.g. for charging a portable computer, mobile phone or other portable device)
In addition to the day-to-day activities of the project, it is expected that the student will participate to the laboratory meetings of our group as well as specific three-way meetings involving the student, her/ his supervisor and a representatives of the Company involved in this project. Objective of these meetings will be to discuss the results of the project carried on by the student, as well as exposing him/her to an industrial environment and technology transfer activities.
