Organic transistors are key elements for flexible, wearable, and biocompatible logic applications. Multiresponsivity is highly sought‐after in organic electronics to enable sophisticated operations and functions. Such a challenge can be pursued by integrating more components in a single device, each one responding to a specific external stimulus. Here, the first multiresponsive organic device based on a photochromic–ferroelectric organic field‐effect transistor, which is capable of operating as nonvolatile memory with 11 bit memory storage capacity in a single device, is reported. The memory elements can be written and erased independently by means of light or an electric field, with accurate control over the readout signal, excellent repeatability, fast response, and high retention time. Such a proof of concept paves the way toward enhanced functional complexity in optoelectronics via the interfacing of multiple components in a single device, in a fully integrated low‐cost technology compatible with flexible substrates.

Semiconducting polymer based X-ray detectors doped with high-Z nanoparticles hold the promise to combine mechanical flexibility and large-area processing with a high X-ray stopping power and sensitivity. Currently, a lack of understanding of how nanoparticle doping impacts the detector dynamics impedes the optimization of such detectors. Here, we study direct X-ray radiation detectors based on the semiconducting polymer poly(9,9-dioctyfluorene) blended with Bismuth(III)oxide (Bi2O3) nanoparticles (NPs). Pure polymer diodes show a high mobility of 1.3 × 10−5 cm2/V s, a low leakage current of 200 nA/cm2 at −80 V, and a high rectifying factor up to 3 × 105 that allow us to compare the X-ray response of a polymer detector in charge-injection conditions (forward bias) and in charge-collection conditions (reverse bias), together with the impact of NP-loading in the two operation regimes. When operated in reverse bias, the detectors reach the state of the art sensitivity of 24 μC/Gy cm2, providing a fast photoresponse. In forward operation, a slower detection dynamics but improved sensitivity (up to 450 ± 150 nC/Gy) due to conductive gain is observed. High-Z NP doping increases the X-ray absorption, but higher NP loadings lead to a strong reduction of charge-carrier injection and transport due to a strong impact on the semiconductor morphology. Finally, the time response of optimized detectors showed a cut-off frequency up to 200 Hz. Taking advantage of such a fast dynamic response, we demonstrate an X-ray based velocity tracking system.

The correlation between morphology and optoelectronic performance in organic thin-film transistors based on blends of photochromic diarylethenes (DAE) and poly(3-hexylthiophene) (P3HT) is investigated by varying molecular weight (M w = 20-100 kDa) and regioregularity of the conjugated polymer as well as the temperature of thermal annealing (rt-160 °C) in thin films. Semicrystalline architectures of P3HT/DAE blends comprise crystalline domains, ensuring efficient charge transport, and less aggregated regions, where DAEs are located as a result of their spontaneous expulsion from the crystalline domains during the self-assembly. The best compromise between field-effect mobility (µ) and switching capabilities is observed in blends containing P3HT with M w = 50 kDa, exhibiting µ as high as 1 × 10 −3 cm 2 V −1 s −1 combined with a >50% photoswitching ratio. Higher or lower M w than 50 kDa are found to be detrimental for field-effect mobility and to lead to reduced device current switchability. The microstructure of the regioregular P3HT blend is found to be sensitive to the thermal annealing temperature, with an increase in µ and a decrease in current modulation being observed as a response to the lightstimulus likely due to an increased P3HT-DAE segregation, partially hindering DAE photoisomerization. The findings demonstrate the paramount importance of fine tuning the structure and morphology of bicomponent films for leveraging the multifunctional nature of optoelectronic devices.