Οργανικά φωτοβολταϊκά υψηλής επίδοσης

Abstract

It is widely recognized that organic photovoltaics have gained the attention of the scientific community, leading to an increase in the number of researches taking place to improve their efficiency. The main reason is their ability to generate low-cost environmental friendly electricity. Moreover, the light weight, flexibility and capability of mass production in modern design along with their ability to be placed on different kind of surfaces have changed the prospect in which energy production is approached. Organic photovoltaics mainly use blends of semiconducting polymers and fullerene derivatives both creating the active layer of the device. This dissertation is divided into three sections. The first section begins with a bibliographic review on photovoltaics in general emphasizing on organic photovoltaics, the different kind of structures they have and the deposition techniques of the active layer. The second section includes a broad reference in polymer-fullerene bulk heterojunction organic photovoltaics, as well as a more detailed analysis in specific ones, along with further reference to non-fullerene acceptors. The section is concluded with the selection of two active layer combinations which will be analyzed in the experimental part of this study. The third part, the experimental one, presents the construction of one of the two selected devices (with the PCDTBT: PC70BM active layer) and analyzes the device’s performance by comparing the results with the theoretical models specifically designed for bulk heterojunction organic photovoltaics. It also includes a presentation of the creation of a ternary system having as an active layer the combination PBDB-T: ITIC: PC70BM. Then, the device’s performance is recorded and analyzed. Finally, the conclusions are obtained with a broader overview of the study and future suggestions for improving the performance and operation of organic photovoltaics.