Highly efficient semitransparent tandem organic solar cells with complementary absorber materials

Abstract

We present highly efficient, semitransparent small molecule organic solar cells. The devices employ an indium tin oxide-free top contact, consisting of thin metal films. An additional organic layer is used to enhance light outcoupling. The solar cell incorporates two stacked subcells, each containing a donor:acceptor bulk heterojunction. The two subcells have complementary absorbers, with separate blue (C60), red (fluorinated zinc phthalocyanine), and green (dicyanovinyl oligothiophene derivative) absorbing molecules. A power conversion efficiency of 4.9 ± 0.2% is obtained for the device having an average transmission of 24% in the visible range.

Flexible and Semitransparent Organic Solar Cells

“…Thus, building tandem architecture www.advenergymat.de by introducing multiple photoactive materials allows fine adjustment of absorption, transparency and efficiency of the devices. [169] Tang et al [170] enhanced PCE of the semitransparent OSCs by connecting the stacked two semitransparent sub-cells in parallel. The total loss of photons from reflection, parasitic absorption, and transmission in the semitransparent tandem solar cell could be smaller than the loss in a single device using the same photoactive materials.…”

Semi-transparent polymer solar cells

“…On the other hand, the limited harvesting at all wavelengths resulting from the low reflectivity of the top electrode can be partially compensated with the incorporation of an additional absorber layer in a tandem configuration. [82][83][84][85] The second approach to increase transparency in the visible spectrum and to limit the loss in PCE is the incorporation of multilayer anti-reflection coatings for the visible or Bragg reflectors to help to trap the near UV and NIR. 41,42,[86][87][88][89][90] The combination of both may further improve the balance between transparency and PCE.…”

Short-Channel Organic Thin-Film Transistors

“…In addition, the 2011 Deutscher Zukunftpreis 4 (German Future Prize) was awarded to Karl Leo, Jan Blochwitz-Nimoth and Martin Pfeiffer for their major contribution in the advancement of organic functional materials and manufacturing techniques, especially for applications in lighting and photovoltaics [64][65][66][67]. Finally, it is worth mentioning that despite all these advances, the field of organic electronics is still in its infancy and there is still much room for improvement and much to be learned and investigated.…”