| Autor: |
Cao B; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada.; National Institute for Nanotechnology, National Research Council Canada , 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada., He X; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada., Sorge JB; Department of Electrical and Computer Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada., Lalany A; Department of Electrical and Computer Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada., Ahadi K; Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada., Afshar A; Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada., Olsen BC; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada.; National Institute for Nanotechnology, National Research Council Canada , 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada., Hauger TC; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada.; National Institute for Nanotechnology, National Research Council Canada , 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada., Mobarok MH; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada., Li P; nanoFAB Centre, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada., Cadien KC; Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada., Brett MJ; Department of Electrical and Computer Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada., Luber EJ; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada.; National Institute for Nanotechnology, National Research Council Canada , 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada., Buriak JM; Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada.; National Institute for Nanotechnology, National Research Council Canada , 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada. |
| Abstrakt: |
Organic solar cells (OSCs) are a complex assembly of disparate materials, each with a precise function within the device. Typically, the electrodes are flat, and the device is fabricated through a layering approach of the interfacial layers and photoactive materials. This work explores the integration of high surface area transparent electrodes to investigate the possible role(s) a three-dimensional electrode could take within an OSC, with a BHJ composed of a donor-acceptor combination with a high degree of electron and hole mobility mismatch. Nanotree indium tin oxide (ITO) electrodes were prepared via glancing angle deposition, structures that were previously demonstrated to be single-crystalline. A thin layer of zinc oxide was deposited on the ITO nanotrees via atomic layer deposition, followed by a self-assembled monolayer of C 60 -based molecules that was bound to the zinc oxide surface through a carboxylic acid group. Infiltration of these functionalized ITO nanotrees with the photoactive layer, the bulk heterojunction comprising PC 71 BM and a high hole mobility low band gap polymer (PDPPTT-T-TT), led to families of devices that were analyzed for the effect of nanotree height. When the height was varied from 0 to 50, 75, 100, and 120 nm, statistically significant differences in device performance were noted with the maximum device efficiencies observed with a nanotree height of 75 nm. From analysis of these results, it was found that the intrinsic mobility mismatch between the donor and acceptor phases could be compensated for when the electron collection length was reduced relative to the hole collection length, resulting in more balanced charge extraction and reduced recombination, leading to improved efficiencies. However, as the ITO nanotrees increased in height and branching, the decrease in electron collection length was offset by an increase in hole collection length and potential deleterious electric field redistribution effects, resulting in decreased efficiency. |
