Achieving high sensitivity in single organic submicrometer ribbon based photodetector through surface engineering

Abstract The performance of the single organic submicrometer ribbon based photodetector has been improved by one order of magnitude by combining a better crystalline structure with proper surface engineering, such as coating a dielectric layer PMMA or PS between the substrate and the organic semiconductor. The photoconductivity gain is as much as 1.3 × 10 4 , the responsivity is about 4372 A W −1 at the field of about 2 × 10 6  V m −1 , and the highest on/off ratio reaches 10 4 . The extremely high gain is attributed to the high mobility and the long photo carrier’s lifetime induced by the dielectric layer.