PHOTOVOLTAIC AND SPECTRAL PROPERTIES OF TETRAPHENYLOPORPHYRIN AND METALLOTETRAPHENYLOPORPHYRIN DYES

Spectroscopical properties and photocurrent (or photovoltage) of tetra phenyloporphyrins and metallotetraphenyloporphyrins in nematic liquid crystal have been studied, Photoelectric response has been measured in an electrochemical cell made of the semitransparent semiconducting an d golden electrodes with porphyrin dyes embedded in liquid crystal, Fl uorescence, time-resolved luminescence in microsecond time scale and p hotoacoustic spectra have also been measured. The competition between radiative, non-radiative processes and charge transfer is discussed. I t has been shown that effectivity of porphyrins for photocurrent gener ation depends on the presence/absence of central metal in the macrocyc le of porphyrin skeleton and the kind of metal, The schematic model of the contributions of the dye molecule and semiconducting electrode in the electron transfer process is shown. (C) 1998 Elsevier Science B.V .