a photosensitive element for electrophotography has an electrically conductive substrate and a layer structure thereon comprising a charge generating substance and a charge transport substance . an improved charge transport substance is a derivative of triphenylamine in which at least 80 % of the electrons in the highest occupied molecular orbital are located on the triphenylamine skeleton . examples of such compounds have the following formula : ## str1 ## wherein x is a an optionally substituted heterocyclic radical containing at least one ring nitrogen , q is a single bond or -- c ═ c --, and z 1 , z 2 and z 3 are h , lower alkyl or alkoxy , aryl , no 2 , cf 3 , -- n 2 , -- s -- c 6 h 5 or -- s 2 .