Solar cells with porphyrin sensitization

Porphyrins have been studied as photosensitizers in two different types of solar cells. In one type of cell, a p-n junction was created with the system ITO/5,10,15,20-tetra(o-nitrophenyl)porphyrinatozinc/Alq(3)/Al. In another type of cell, porphyrins with carboxyphenyl and aminophenyl substituents were used as photosensitizers for a nanoparticulate TiO2 (Gratzel) cell in which photoelectropolymerization of aniline created polyaniline as a hole transport medium. Optimum results from such cells gave an open-circuit voltage (V-oc) of 0.6 V, a short-circuit current (J(sc)) of 0.2 mA/cm(2), a fill factor of 0.7, and a conversion efficiency of 2.4% under 4.4 mW/cm(2) of simulated solar intensity. Such cells offer a promising new approach to a solid-state Gratzel cell. (C) 2002 Elsevier Science B.V. All rights reserved.