Electrical Conductivity of 1,4- Dihydroxyanthraquinone and the Complex Silver/ Dihydroxyanthraquinone

摘要

Quinizarin (1,4-DHAQ) and Ag/1,4-DHAQ thin films deposited under vacuum were investigated by Ⅰ- Ⅴ measurements at various temperatures. It is shown that when submitted to an electric field of 5x10~5 V cm~(-1) or less, the Ⅰ-Ⅴ characteristics of Al/DHAQ/Al sandwich structures are ohmic. The temperature dependence is I∝ exp(-ΔE/κT). The measured activation energy is 0.3 eV in the case of pure DHAQ and 30 meV in the case of Ag/DHAQ. Therefore we can imagine that in the former case the conductivity is controlled by thermally activated hopping above intermolecular barriers, while in the latter case the conductivity can be attributed to tunnelling between silver grains.