Structure-function relationships in unsymmetrical zinc phthalocyanines for dye-sensitized solar cells.
A series of unsymmetrical zinc phthalocyanines bearing an anchoring carboxylic function linked to the phthalocyanine ring through different spacers were designed for dye-sensitised solar cells (DSSC). The modification of the spacer group allows not only a variable distance between the dye and the nanocrystalline TiO(2), but also a distinct orientation of the phthalocyanine on the semiconductor surface. The photovoltaic data show that the nature of the spacer group plays a significant role in the electron injection from the photo-excited dye into the nanocrystalline TiO(2) semiconductor, the recombination rates and the efficiency of the cells. The incident monochromatic photon-to-current conversion efficiency (IPCE) for phthalocyanines bearing an insulating spacer is as low as 9%, whereas for those with a conducting spacer an outstanding IPCE 80% was obtained.
Cid
Juan-José
JJ
Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
García-Iglesias
Miguel
M
Yum
Jun-Ho
JH
Forneli
Amparo
A
Albero
Josep
J
Martínez-Ferrero
Eugenia
E
Vázquez
Purificación
P
Grätzel
Michael
M
Nazeeruddin
Mohammad K
MK
Palomares
Emilio
E
Torres
Tomás
T