Among the photovoltaic technologies, organic solar cells are the most suitable ones to textile structures in terms of favorable features such as flexibility, lightness, cost-effectiveness and usage performance. Studies about photovoltaic textiles consider two main approaches: First, solar cell is formed elsewhere and then, photovoltaic structure is integrated in/onto textiles using various techniques, i. e. patching. Second, solar cell is formed in fiber or textile form. So, it can be used as fiber itself or can form textile structures, which are partly or completely photovoltaic. Shelf lifetime, cost and efficiency of organic solar cells are still important issues for also photovoltaic fibers and textiles to be overcome before commercialization.
Utilizing flexible solar cells with textiles can open many application fields for photovoltaic textiles such as electronic textiles besides powering movable electronic devices. Solar cell integrated bags, jackets and dresses are some of the recent applications of polymer based solar cells. For example, in study of Krebs et al. (2006) incorporation of polymer based organic solar cells into textile structures were performed by two ways: In first one, PET substrate was coated with ITO, MEH-PPV, C60 and Al, respectively. Then, device was laminated using PET. In second one, PE layer was laminated onto textile substrate. Then, by applying PEDOT, active material and final electrode, respectively, device was completed. Completed devices were integrated into clothes (Fig. 10).
Fig. 10. An example of patterned polymer solar cells on a PET substrate incorporated into clothing by sewing through the polymer solar cell foil using an ordinary sewing machine. Connections between cells were made with copper wire that could also be sewn into the garment. The solar cells were incorporated into a dress and a belt. Design by Tine Hertz Reprinted from Sol. Energy Mater. Sol. Cells, 90, Krebs F. C.; Biancardo M.; Jensen B. W.; Spanggard H. & Alstrup J., Strategies for incorporation of polymer photovoltaics into garments and textiles, 1058-1067, Copyright (2006), with permission from Elsevier.