Abstract
Abstract We discover photo-current generation at SWNT-electrode contact at zero bias. The directions of this current can be controlled via focusing the laser bean (532 nm) on different position of the SWNTs film; meanwhile, current can be significantly amplified by a factor of 1.5 under bias voltage operation. Phenomenon resembles the conventional S-based Schottky diodes and underlying mechanism involves reduction of barrier height and widening of depletion region upon bias application. In addition, we have shown here that flashing of SWNT films in vacuum and air causes nanotube cutting and O2 desorption, followed by re-adsorption of O2. The cutting at Fe-defect entities is triggered via extra heat provided by photo-induced chemical reaction. Considerable amount of heat released by oxide and CO2 formations assists cutting process along tube circumference. Our systematical experiments consist of SWNT films flashed in vacuum, air and atmospheric N2 respectively, in conjunction with resistance measurements. The variation of film resistance with lighting shows stepwise profiles and similar effect is also present in treated SWNT film. In the end, we hope to establish possible models of the photo-generated current in SWNTs film and the flashing effect, furthermore, the rationalization of relevant mechanism has also been attempt.