High‐Performance Broadband Multiplier‐Type Organic Photodetectors Based on Quaternary Heterojunctions

Abstract To enhance the near‐infrared detection capability and broaden the response spectrum of single‐carrier‐transport‐based multiplication‐type organic photodetectors (PM‐OPDs), a quaternary heterojunction strategy based on double donors and double receptors is employed. The quaternary PM‐OPDs with the configuration ITO/PEDOT:PSS/Active‐layer/Al are meticulously fabricated. The experimental results revealed that the optimized quaternary heterojunction PM‐OPDs based on P3HT:PTB7‐Th:PC 61 BM:Y6 (40:60:3:2 wt/wt/wt/wt) achieved a wide spectral response from 300 to 980 nm. Under a bias voltage of −20 V and illumination at 850 nm with a power density of 1 mW cm −2 , the PM‐OPDs with the optimal weight ratio achieved the following performance metrics: an external quantum efficiency of 8555.89%, a specific detectivity of 6.36 × 10 11 Jones, a responsivity of 58.66 A/W, a photocurrent gains of 963.16%, and a noise equivalent power of 4.10 × 10 −13 W/Hz 1/2 . Such remarkable near‐infrared detection capability and broad spectral response can be attributed to the introduction of PTB7‐Th and Y6, which enhanced the photon capture, exciton dissociation, and electron trapping abilities within the active layer, as well as the creation of cascaded energy levels that facilitated more efficient carrier transport. This study provides a feasible reference for developing and fabricating high‐performance organic photodetectors.