CNT/Cu₂O heterojunction via self-assembly technology for emerging flexible photodetectors

The unique properties of carbon nanotubes (CNTs)/metal oxide semiconductor (MOS) have contributed to rapid expansion of flexible/wearable optoelectronic devices. Exploring the band structure, light-harvesting ability, carrier mobility of CNT/MOS heterojunction still undergoes an enormous challenge. Herein, we report a novel, effective strategy to preparation of the Cu₂O–OH functioned CNT. First, CNT is functioned to the formation of –OH groups of the walls. The Cu²⁺ ions are anchored through a strong affinity with –OH groups. The formation of CNT/Cu₂O heterojunction demonstrates the conspicuous enhancement of the light-absorption, charge separation efficiency and photoelectric properties compare with the pure CNTs and Cu₂O. Moreover, the CNT in the composites plays a crucial part in trapping electrons. In the meantime, the Cu₂O can emerge as an electron donor due to the inspiration for visible light. The experimental results offer a new strategy for the ingenious collocation and the rising advancement of MOS. The research ideas shed light on the applications of CNT-based materials.