Function separated photosensitive member having a diphenylamine derivative disazo charge generation material

A function separated type electrophotographic photosensitive member for infrared rays, comprising a combination of a charge generation material and a charge transport material, wherein the electrophotographic photosensitive member for infrared rays contains as the charge generation material a disazo pigment represented by Formula ( 1) shown below.

• Formula (1):
• ##STR22## wherein R.sub.1 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted acryl group or a substituted or unsubstituted heterocyclic group;
• R.sub.2 and R.sub.3 each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a halogen atom, a nitro group, a cyano group or a trifluoromethyl group;
• and X.sub.1, X.sub.2, X.sub.3 and X.sub.4 each represent a hydrogen atom or a halogen atom, except, however, the case where all of them are hydrogen atoms.