Tape-Based Photodetector: Transfer Process and Persistent Photoconductivity

We report a facile transfer method to fabricate flexible photodetectors directly on tape, wherein the films formed by different processes were integrated together. The tape-based photodetectors with CdS nanowire (NW) active layers exhibited good performances as those fabricated by conventional processes. The obvious persistent photocurrent in our device was eliminated by introducing a conductive polymer poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) onto the CdS NW layer. By adjusting the concentration of the PEDOT:PSS aqueous solution, a device with a fast response, ultrashort decay time, and relatively large photocurrent was obtained. The decay times were 11.59 and 6.64 ms for devices using electrodes of silver NWs and gold, respectively. These values are much shorter than the shortest decay times (on the order of hundreds of milliseconds) reported previously.