An optically transparent and electrically conductive film composed of metal nanowires or carbon nanotubes combined with pristine graphene with a metal nanowire-to-graphene or carbon nanotube-to-graphene weight ratio from 1/99 to 99/1, wherein the pristine graphene is single-crystalline and contains no oxygen and no hydrogen, and the film exhibits an optical transparence no less than 80% and sheet resistance no higher than 300 ohm/square. This film can be used as a transparent conductive electrode in an electro-optic device, such as a photovoltaic or solar cell, light-emitting diode, photo-detector, touch screen, electro-wetting display, liquid crystal display, plasma display, LED display, a TV screen, a computer screen, or a mobile phone screen.