Details

Autor(en) / Beteiligte

• Huynh, W.U.
• Dittmer, J.J.
• Libby, W.C.
• Whiting, G.L.
• Alivisatos, A.P.

Titel

Controlling the Morphology of Nanocrystal-Polymer Composites for Solar Cells

Ist Teil von

• Advanced functional materials, 2003-01, Vol.13 (1), p.73-79

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2003

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• We have shown recently that the use of high‐aspect‐ratio inorganic nanorods in conjunction with conjugated polymers is a route to obtaining efficient solar cells processed from solution. Here, we demonstrate that the use of binary solvent mixtures in which one of the components is a ligand for the nanocrystals is effective in controlling the dispersion of nanocrystals in a polymer. By varying the concentration of the solvent mixture, phase separation between the nanocrystal and polymer could be tuned from micrometer scale to nanometer scale. In addition, we can achieve nanocrystal surfaces that are free of surfactant through the use of weak binding ligands that can be removed through heating. When combined, the control of film morphology together with surfactant removal result in nanorod–polymer blend photovoltaic cells with a high external quantum efficiency of 59 % under 0.1 mW cm–2 illumination at 450 nm. Highly efficient solar cells can be fabricated from a hybrid nanorod–polymer solution when precise control of the film morphology can be achieved. The morphology of thin films from blends of CdSe and poly(3‐hexylthiophene), which is easily studied via atomic force microscopy (see Figure, 5 μm2 scan area), can be finely tuned through the use of a binary solvent mixture and thermal treatment for impressive increases in device efficiency.