A High-Performance Self-Powered UV Photodetector Based on Self-Doping TIO2 Nanotube Arrays

In this paper, we present a high-performance self-powered ultraviolet (UV) photodetector using electrochemical micro-porous-channel arrays based on a cost-effective and environment-friendly black TiO
₂
nanotube arrays (BTNAs) and polysulfide (S
^2-
/S
_x
^2-
) electrolyte. By self-doping TiO
₂
the concentration and lifetime of UV photo-generated carriers are increased due to increasing oxygen vacancies and Ti
³⁺
defects in BTNAs, effectively enhancing the carrier transport and multiple exciton effect of carriers, and thus the self-powered UV photodetector based on electrochemical micro-porous-channel arrays demonstrates a high photoresponsivity of ~22 mA/W and high-speed photoresponse of ~4 ms in rise and decay time.