Patent ID: 7282636

Claim:
A photoelectric energy conversion element comprising: a semiconductor film electrode having a semiconductor layer comprising a semiconductor material and one or more lignin derivatives which absorb light and photosensitize said semiconductor material; the lignin derivatives selected from the group consisting of (a) through (e): (a) a lignophenol derivative or a phenol derivative of lignin that is prepared by solvating a lignin-containing material with a phenol compound and adding an acid to the solvate; (b) a secondary derivative that is prepared by one reaction of the lignophenol derivative (a) selected from the group consisting of acylation, carboxylation, amidation, introduction of a crosslinking group, and alkali treatment; (c) a higher-order derivative that is prepared by at least two reactions of the lignophenol derivative (a) selected from the group consisting of acylation, carboxylation, amidation, introduction of a crosslinking group, and alkali treatment; (d) a crosslinked secondary derivative that is prepared by crosslinking the secondary derivative (b) obtained by the introduction of the crosslinking group; (e) a crosslinked higher-order derivative that is prepared by crosslinking the higher-order derivative (c) obtained by the introduction of the crosslinking group; a charge transfer layer; and a counter electrode.