Multifunctional Photodetector with Tunable Response Bandwidth and Polarization Sensitivity

Abstract Multifunctional organic photodetectors (MFOPDs) have garnered significant attention due to their remarkable potential for integrating diverse device functionalities. In contrast to previous MFOPDs that have primarily emphasized the integration of various response bands, a pioneering multifunctional photodetector is introduced based on the P3HT:PC 61 BM system capable of selectively responding to both wavelength and polarization. Under positive bias, the device operates in a wide‐band, polarization‐insensitive mode, achieving an external quantum efficiency (EQE) of up to 7.01 × 10 4 %. The EQE dichroic ratio (DR) of the device remains <1.01 (at 650 nm). Conversely, under negative bias, the device transitions into a narrow‐band, polarization‐sensitive mode, achieving an EQE of up to 4.82 × 10 4 % with a narrow full width at half maximum (FWHM) of only 25 nm at 650 nm. The EQE DR exceeds 10 in this mode, marking it as one of the highest values within the field of polarization‐sensitive organic photodetectors. This versatile operation is made possible through the strategic use of double‐sided barriers, an oriented light harvesting layer, and a charge injection narrowing (CIN) approach. This work represents a significant advancement toward the realization of multifunctional photodetectors capable of selecting response bands and polarization sensitivity.