Suppressing Carrier Recombination in BiVO4/PEDOT:PSS Heterojunction for High-Performance Photodetector

The organic-inorganic hybrid heterojunction is introduced for the first time to break through the performance bottleneck of BiVO4-based photodetectors. Through a facile solution process, a p-n heterojunction is established at the BiVO4/PEDOT:PSS interface, and the built-in electric field is designed to separate photogenerated charge carriers. The hybrid heterojunction outputs a significantly increased photocurrent, which is 24 000 times larger than that of the bare BiVO4 thin film. The photodetector shows a satisfactory performance with a responsivity (R) and specific detectivity (D*) of 107.8 mA/W and 4.13 × 1010 Jones at 482 nm illumination. In addition to the fast response speed (100 ms), the device also exhibits an impressive long-term stability with a negligible attenuation in photocurrent after more than 700 cycles. This work provides a novel strategy to suppress carrier recombination of BiVO4, and the coupling of metal oxides and organic semiconductors opens up a new avenue for fabricating high-performance photodetectors.