Arylamines selected for the hole transporting layer which generally is of a thickness of from about 5 microns to about 50 microns, and preferably of a thickness of from about 10 microns to about 40 microns, include molecules of the following formula: ##STR7## dispersed in a highly insulating and transparent organic resinous binder wherein X is an alkyl group or a halogen, especially those substitu