Development of Carbon Nanotube Based Organic Solar Cells with High Efficiency

(Prof.Dr.Nilgün KARATEPE YAVUZ, Prof. Dr. Üner ÇOLAK, Doç.Dr. Elif ARICI, Fatma Çolak, Zeynep Dalkılıç, Osman Ürper)


 In this project, in order to improve the efficiency of polymer-based solar cells, we will use the carbon nanotubes that are produced in our laboratory (CNT), instead of most widely used in scientific publications, poly (3-hexylthiophene) and high resolution buckminsterfullerene derivatives. Intrinsic p-type conductive CNT coatings can be converted to using very low amounts of additives (MoOx, HNO3, etc.), 85% - 90% light-transmissive conductive layers. CNT doping increases the amount of free electorns as well as reduces the resistance between the tubes and brings the conductivity of the CNTs to the level of the semiconductor or metal depending on the doping concentration. Metallic CNTs can be used instead of expensive and fragile structure of indium tin oxide (ITO) tranparent electrode. Organic solar cells which are developed instead ITO using CNTs have cell efficiencies around 1.4-2.3 %. When the produced CNT electrodes are vertical to the base of solar cell, sunlight wiil be reflected multiple times between the electrodes to result in a more efficient light collection. This mechanism successfully evaluated for inorganic solar cell systems [8,9], but never tested for polymer systems before. The scope of the project is planned for the development of a similar systems and predominantly p-type conductive CNTs will be examined the role of light-absorbing material in organic solar cells. p-CNT/n-type semiconductor thin film will be placed on standard organic solar cell and perfomance of multijunction solar cells which is called 'tandem' will be evaluated.


                Figure: The project targeted polymer bulk heterojunction systems