A new form of hydroxyaluminum phthalocyanine by acid treatment. Characterization and photoactivity

Abstract

A new polymorph of hydroxyaluminum phthalocyanine (PcAlOH) was obtained when PcAlOH thin film was exposed to aqueous acid solutions. The new polymorph, which is characterized by infrared, near-infrared, and visible absorption spectrometry and X-ray diffractometry, shows enhanced photoactivity in a photoelectrochemical solar cell device. LB H. DAO, GBRARD PERRIER et KENNETH COLE. Can. J . Chem. 66, 1609 (1988). Une nouvelle forme de phtalocyanine d'hydroxyaluminium (PcAlOH) a t t t obtenue quand on traite des films minces de PcAlOH avec des solutions aqueuses d'acides. Le nouveau polymorphe qui a Ctt caracttrist par les spectroscopies infrarouge, infrarouge proche et visible, et par la diffraction aux rayons X, dtmontre une activitt accrue lors de son utilisation dans une cellule solaire phototlectrochirnique.

Spectral Cosensitization in Phthalocyanine‐Porphyrin Photoelectrochemical Cells

“…~-PcAIOH-TPPAIOH electrode.-- Figure la shows the absorption spectrum of a PcA1OH thin film (400A), which presents the two characteristic peaks of the q-form at 640 and 830 nm (2)(3)(4). Sublimation of a thin film (250A) of TPPAIOH on the PcAIOH layer results in the appearance of new absorption peaks at 430 and 530 nm (Fig.…”

“…Broadening of the action spectra has been noted for triand tetravalent, metal pbthalocyanine compared with divalent metal and H~-phthalocyanine thin film photoelectrodes (1). An acid treatment leads to a spectral broadening and significant improvement of the photoelectrochemical characteristics of thin films of hydroxyaluminum phthalocyanine (PcA1OH) (2)(3)(4). However, the spectral response in these cells is still limited to the range 550-900 nm.…”