A highly sensitive and self-powered ultraviolet photodetector composed of titanium dioxide nanorods and polyaniline nanowires

• A UV photodetector composed of TiO2 and PANI was designed and fabricated.
• The fabrication method of the UV photodetector was simple and convenient.
• The UV potodetector device had excellent sensitivity to UV light.
• The UV potodetector had different sensitivities to different wavelengths UV light.

A highly sensitive and self-powered ultraviolet (UV) photodetector was fabricated using a low-cost, low temperature and convenient process. The designed multilayer structure device was a self-powered UV photodetector based on p–n hetero-junction and it was composed of two layers of n-type titanium dioxide nanorods (TiO2 NRs) and one layer of p-type polyaniline nanowires (PANI NWs). The TiO2 NRs were synthesized by a hydrothermal method and the PANI NWs were synthesized by a chemical oxidation method. The morphologies of TiO2 NRs and PANI NWs were characterized by scanning electron microscopy (SEM). The I–t and I–V curves of the nanodevices were measured by a CHI660D electrochemical workstation. The fabricated UV photodetector with the TiO2/PANI/TiO2 multilayer structure was able to work without any external power source and generated different photocurrents when irradiated with different wavelengths UV light, that is to say it exhibited excellent sensitivity to UV light.