Improved Performance of Polymer:Polymer Solar Cells by Doping Electron-Accepting Polymers with an Organosulfonic Acid
(4527–4534)Advanced Functional Materials 21  #23 (2011)
Nam et al, South Korea, improved the performance of polymer:polymer solar cells that are made using blend films of poly(3-hexylthiophene) (P3HT) and poly(9,9-dioctylfluorene-co- benzothiadiazole (F8BT) by doping the F8BT polymer with an organosulfonic acid [4-ethylbezenesulfonic acid (EBSA)].  The F8BT-EBSA films exhibit huge photoluminescence quenching, ionization potential shift toward lower energy, and greatly enhanced electron mobility. The short-circuit current density of solar cells is improved by ca. twofold (10 wt.% EBSA doping), while the open-circuit voltage increases by ca. 0.4 V. Consequently, the power conversion efficiency was improved by ca. threefold, even though the optical density of the P3HT:F8BT-EBSA blend film is reduced by 10 wt.% EBSA doping due to the nanostructure and surface morphology change.  (RDC 12/6/2011)

2/25/2011
Influence of the size-controlled TiO2 nanotubes fabricated by low-temperature chemical synthesis on the dye-sensitized solar cell properties
(1749-1757) Journal of Materials Science 46 #6 (2011)
Kim, Sekino and Tanaka, Japan showed that this controlled TiO2 photoelectrode architecture enhanced conversion efficiency without TiCl4 treatment.  (RDC 2/22/2011)

The Effects of Co-Sensitization and Electronic Structure of Nanocrystalline N/TiO2 Anode on the Performance of Dye-Sensitized Solar Cells
(150-156) Journal of Inorganic and Organometallic Polymers and Materials 21  #1 (2011)
Zhang et al , China obtained N/TiO2 nanocrystalline film anodes were obtained by doping nonmetallic element N which could change the LUMO of anode.  The match between the LUMO energy lever of N/TiO2 anode and the dye was studied, which led to the easy injection of electron from the excited state of dye molecule to the conduction band of semiconductor, and thus improved the photoelectric conversion efficiency and reduced the impedance of solar cells.  (RDC 2/21/2011)

1/21/2011
Indium tin oxide nanopillar electrodes in polymer/fullerene solar cells
(# 085706) Nanotechnology 22 #8 (2010)
Rider et al of the University of Alberta, Canada and Western Washington University, Washington  used indium tin oxide (ITO) and hybrid ITO/SiO2 nanopillars as three-dimensional high surface area transparent electrodes in organic photovoltaics. The resulting power conversion efficiency is 2.2% which is a third greater than for devices prepared on commercial ITO. To further refine the structure, insulating SiO2 caps are added above the GLAD ITO nanopillars to produce a hybrid ITO/SiO2 nanoelectrode. photovoltaic devices based on this system show reduced electrical shorting and series resistance, and as a consequence, a further improved power conversion efficiency of 2.5% is recorded.  (RDC 1/21/2011)

1/21/2011
Impact of the Alkyl Side Chains on the Optoelectronic Properties of a Series of Photovoltaic Low-Band-Gap Copolymers
(9779–9786) Macromolecules 43 #23 (2010)
Biniek  et al of the University of Strasburg, France synthesized  a series of photovoltaic copolymers with a common conjugated backbone and differing solubilizing side chains. The side chains have a major impact on the material and device properties. The electronic band gap can be varied by more than 0.3 eV, the charge mobilities by orders of magnitude, and the optimized fullerene content of photovoltaic devices by a factor of 4 by barely changing the side-chain positioning and/or by switching from linear to branched alkyl chains. A power conversion efficiency of 2.7% could be achieved with devices using the most promising polymer.  (RDC 1/18/2011)