Effect of thermal annealing on the photoconductivity of self-assembled porphyrin nanowires

We investigated the effects of thermal annealing on the photoconductivity of self-assembled meso-tetra-(4-sulfonato-phenyl) porphine (TPPS4) nanowires. As the temperature increases from 24˚C to 70˚C, persistent current (dark current) and non-persistent current (photocurrent) initially increase before decreasing below their initial values prior to heating. The annealing causes no permanent change in photoconductivity, although atomic force microscopy images showed change in the height of nano-rods before and after the annealing. A theoretical explanation for this behavior is proposed based on a Schottky barrier model described in previous research.[1]

1- C.K. Riley et al., J. Phys. Chem. C 2010, 114, 19227–19233