Semiconductivity and photoconductivity studies of metal complexes of 5,14-dihydrodibenzo[b,i][1,4,8,11]tetra-azacyclotetradecine single crystals

The semiconductivity properties of the single-crystal metal complexes between Co2+, Cu2+ and Ni2+ and 5,14-dihydrodibenzo[b, i][1,4,8,11]tetra-azacyclotetradecine (tada) in vacuum and NO2 are reported. The electron-acceptor gas, NO2, produced an increase in conductivity by decreasing the thermal activation energy for conduction compared with vacuum. Photoconduction spectra and photocurrent kinetic measurements are reported for each complex, with varying temperature and ambient atmosphere. The photocurrent rise and decay times for this class of material as a whole are found to be long compared with the larger phthalocyanine complexes, suggesting that the crystals are less perfect.