Flexible electrically pumped random lasing from ZnO nanowires based on metal-insulator-semiconductor structure

Flexible electrically pumped random laser (RL) based on ZnO nanowires is demonstrated for the first time to our knowledge. The ZnO nanowires each with a length of 5 μm and an average diameter of 180 nm are synthesized on flexible substrate (ITO/PET) by a simple hydrothermal method. No obvious visible defect-related-emission band is observed in the photoluminescence (PL) spectrum, indicating that the ZnO nanowires grown on the flexible ITO/PET substrate have few defects. In order to achieve electrically pumped random lasing with a lower threshold, the metal-insulator-semiconductor (MIS) structure of Au/SiO₂/ZnO on ITO/PET substrate is fabricated by low temperature process. With sufficient forward bias, the as-fabricated flexible device exhibits random lasing, and a low threshold current of ~11.5 mA and high luminous intensity are obtained from the ZnO-based random laser. It is believed that this work offers a case study for developing the flexible electrically pumped random lasing from ZnO nanowires.