Photoconductor Fatigue. 1. Photochemistry of Hydrazone-Based Hole-Transport Molecules in Organic Layered Photoconductors: Spectroscopic Characterization and Effect on Electrical Properties

The hole transport molecule p-(diethylamino)benzaldehyde diphenylhydrazone (DEH) undergoes a photochemical reaction to an indazole derivative when exposed to light with λ ≤ ~480 nm. When contained in the hole-transport layer of an organic photoconductor formulation, a clear and direct relation is found between the DEH photochemistry and an increase in the residual surface voltage during light decay of the organic photoconductor. Spectroscopic data and electrical properties measurements with DEH and its derivatives firmly establish this correlation. The increase in residual surface voltage is attributed to the trapping of holes in the charge-transport layer during light decay. © 1991, American Chemical Society. All rights reserved.