The photoresponse of spray-coated and free-standing carbon nanotube films with Schottky contacts

We report on the photocurrent response of carbon nanotube (CNT) films attached to metallic electrodes. By varying the electrode material, we show that the height of the Schottky barrier at the CNT-metal interface is responsible for the relative magnitude of the photocurrent. We find that the time response associated with this photocurrent varies with the spacing between the electrodes and with the method used to fabricate the CNT film. We also calculate the fill factor associated with these devices to be approximately 25%, independently of the type of the CNT film.