Deep ultraviolet-to-NIR broad spectral response organic photodetectors with large gain

Abstract

We developed organic photodetectors with high photocurrent gain by enhancing the electron tunneling from the electrode owing to the effect of interface charge trapping. Furthermore, we utilized a down-conversion material to enhance the photoresponse in the deep-ultraviolet (UV) range. As a result, the photodetectors achieved an external quantum efficiency (EQE) of as high as 4000% while the photoresponsivity remained at 9 A W⁻¹ at the UV wavelength of 250 nm. Finally, a high-performance organic photodetector with broad-photoresponse covering the spectral range from deep-UV (200 nm) to near-infrared (1000 nm) was successfully realized. The maximum EQE exceeds 10 000% at a wavelength of 780 nm, and the photoresponsivity and specific detectivity are up to 70 A W⁻¹ and 4 × 10¹² Jones, respectively.