Electric Properties of the Single-crystal and Thin Film of α,α′-Diphenyl-β-picrylhydrazyl

Abstract

The electronic conductivity of two forms of α,α′-diphenyl-β-picrylhydrazyl, the single crystal and the thin film, was observed. The resistivity (ρ15) at room temperature along c-axis (1×1010 Ω cm.) is 105 times lower than that perpendicular to the axis (1×1015 Ω cm.), but its activation energy (Δε) against temperature is in good agreement (1.5 and 1.6 eV.). These large anisotropy may be introduced from that of the arrangement of molecules in the crystal. In the case of thin film, the values of ρ15 and of Δε are ∼1010 Ω cm., 1.7 eV. for surface type cell and ∼1013 Ω cm., 2.7 eV. for sandwich-type cell respectively. A great difference on the characteristics of photoconduction and on the current-voltage relation in these two types of cell was found.