Efficient Shortwave Infrared Photodetection Through Polymer:Cocrystal Blend Film‐Based Field‐Effect Transistors

Abstract Short‐wave infrared (SWIR) organic photodetectors (OPDs) offer flexibility, cost‐effectiveness, and tunable properties that differentiate them from commercially inorganic SWIR photodetectors. These detectors mainly rely on materials possessing SWIR absorption properties. However, the synthesis of new organic semiconductor materials with narrow band gaps remains a significant challenge. Here an effective and general strategy of blending the TMBP‐F 4 TCNQ (TMF4) cocrystal with the PDVT‐10 polymer as SWIR‐absorbing materials for photoelectronic detection is reported. As prepared field‐effect transistor (FET) device with Si/SiO 2 /PDVT‐10:TMF4 (PTF)/Au configuration presents hole mobility up to 1.70 cm 2 V −1 s −1 and SWIR spectral response range of 1000–1700 nm. Surprisingly, remarkable photoresponsivity (R, 801 A W −1 ) and detectivity (D*, 1.6 × 10 13 Jones) are obtained at 1060 nm. The PTF film exhibits high surface potential of 180 mV, and ultrafast hole transfer within 150 fs when exposed to 1350 nm pump laser. The existence of mobile electrons in TMF4 and the photogeneration of additional carriers upon illumination may create a (photo)doping effect that allows higher hole concentration in PDVT‐10. Significantly, this strategy enhances SWIR detection, therefore showing great prospects in the field of SWIR imaging.