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Organic conducting polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has garnered enormous attention in organic electronics due to its low-cost solution processability, highly tunable conductivity, superior mechanical flexibility, and good biocompatibility together with excellent atmospheric stability. Nevertheless, limited electrical properties and unfavorable water instability of pristine PEDOT:PSS film impede its further implementation in a broad spectrum of practical applications. In this work, the successful tailoring of the intrinsic electrostatic interaction within PEDOT:PSS and consequent optimized electrical properties are enabled by a simple yet effective ionic salt post-treatment strategy. The choice of zinc di[bis(trifluoromethylsulfonyl)imide] (Zn(TFSI)2) not only endows the post-treated PEDOT:PSS film with high electrical properties but also other compelling characteristics, including superior water stability, excellent mechanical flexibility, and fast humidity responsiveness. Multidimensional characterizations are conducted to gain in-depth insights into the mechanisms underlying such improved performance, ranging from intermolecular interactions, polymer conformations, and doping levels to microstructural characteristics. Benefiting from these versatile properties, the as-prepared freestanding Zn(TFSI)2-post-treated PEDOT:PSS films can serve as promising candidates for high-performance polymeric materials integrated into multifunctional flexible electronics, including thermoelectric power generators, conductive hydrogels, and humidity-responsive actuators. This study demonstrates a facile methodology for the exploration of multifunctional conducting polymers, whose implications can extend across a wide range of next-generation wearable devices, bioelectronics, and soft robotics.

The conductive polymer blend poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), popular for numerous organic applications, is investigated in terms of the influences that ionic liquid (IL) treatment and ambient humidity have on its conductivity properties. PEDOT:PSS thin films posttreated with different concentrations of the IL 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA) are exposed to different relative humidity (RH) steps from 0% RH up to 90% RH. Simultaneously, the film swelling and increase in the scattering length density (SLD), indicating a water uptake of the films, are monitored in situwith spectral reflectance (SR) and time-of-flight neutron reflectometry (ToF-NR). Additional in situelectrochemical impedance spectroscopy (EIS) shows that the pristine PEDOT:PSS has only an electronic conductivity, while for the IL-treated samples, an additional ionic conductivity contribution is observed. Upon humidity increase, the electronic conductivity of all PEDOT:PSS thin films decreases, while the ionic conductivity for IL posttreated thin films is enhanced by the intake of water molecules.

Hybrid plasmonic nanostructures have gained enormous attention in a variety of optoelectronic devices due to their surface plasmon resonance properties. Self-assembled hybrid metal/quantum dot (QD) architectures offer a means of coupling the properties of plasmonics and QDs to photodetectors, thereby modifying their functionality. The arrangement and localization of hybrid nanostructures have an impact on exciton trapping and light harvesting. Here, we present a hybrid structure consisting of self-assembled gold nanospheres (Au NSs) embedded in a solid matrix of PbS QDs for mapping the interface structures and the motion of charge carriers. Grazing-incidence small-angle X-ray scattering is utilized to analyze the localization and spacing of the Au NSs within the hybrid structure. Furthermore, by correlating the morphology of the Au NSs in the hybrid structure with the corresponding differences observed in the performance of photodetectors, we are able to determine the impact of interface charge carrier dynamics in the coupling structure. From the perspective of architecture, our study provides insights into the performance improvement of optoelectronic devices.

Tactile perception systems as the medium between the ambient environment and robotics lie in the heart of modern artificial intelligence. By providing different electronic readouts under various circumstances, they can give easily captured information for post-processing. However, for applications of most reported tactile perception systems, external location assistances are still needed. Here, as inspired by the platypus’ sixth sense, we developed a new kind of tactile perception system based on triboelectric sensors with the additional function from quantum rods. This terminal can be used as a single-electrode mode triboelectric nanogenerator for both location detection and vertical force sensing with high sensitivity and fast response. Moreover, by adding CdSe/CdS quantum rods into an imprinted polydimethylsiloxane film, different lateral stretching levels can be perceived by a modified luminescence. Supported by the machine learning technology, the as-fabricated tactile perception system finally obtains an excellent recognition accuracy among 18 different objects of 98.5% on a micro-controller unit platform, which provides an easy pathway in smart home robotics for intelligent sorting.

Realization of multi-source energy harvesting with one single device would maximize power output. Thus, it is emerging as a promising strategy towards renewable energy generation and has attracted worldwide attention in the past decades. Capable of capturing mechanical energy that is ubiquitous in the ambient environment, triboelectric nanogenerator (TENG) has been considered a novel yet effective source towards next-generation energy harvesting. In this work, a flexible hybrid energy harvester (HEH) is developed viathe rational integration of autonomous self-healing TENG and high bending-stable lead sulfide quantum dot (PbS QD) solar cell, enabling independent electricity generation by two different mechanisms. The single-electrode mode TENG component with self-healing is realized by a polydimethylsiloxane/Triton X-100 (PDMS/TX100) mixture as the dielectric layer and the shared gold (Au) electrode, which generates 0.39µA of output current (Iout), 24.6V of output voltages (Vout), 15.4 nC of transfer charges (Qsc), and 7.80mWm-2of output power peak density. The thin-film solar cell component is based on a PbS QD layer as the light absorber with a planar structure fabricated under low-cost and compatible conditions, achieving 22.8mAcm-2of short-circuit current density (Jsc) and 4.92% of power conversion efficiency (PCE). As a proof of concept, an electronic watch is successfully powered by harnessing ambient mechanical and solar energy with a hybridized energy cell. This approach will offer more opportunities to construct a versatile platform towards remote monitoring and smart home systems.

Asymmetric fused-ring electron acceptors (a-FREAs) have proved to be a promising type of electron acceptor for high-performance organic solar cells (OSCs). However, the relationship among molecular structures of a-FREAs and their nanoscale morphology, charge-carrier dynamics, and device performance remains unclear. In this contribution, two FREAs differing in conjugated backbone geometry with an asymmetric conformation (IPT-2F) or symmetric one (INPIC-2F) are selected to systematically explore the superiorities of the asymmetric conformation. Despite the frailer extinction coefficient and weaker crystallinity, IPT-2F shows stronger dipole interactions in the asymmetrical backbone, which would induce a closer lamellar packing than that of the symmetrical counterpart. Using PBDB-T as the electron donor, the IPT-2F-based OSCs achieve the best power conversion efficiency of 14.0%, which is ca. 67% improvement compared to the INPIC-2F-based ones (8.37%), resulting from a simultaneously increased short-circuited current density (Jsc) and fill factor. Systematical investigations on optoelectronic and morphological properties show that the asymmetric conformation-structured IPT-2F exhibits better miscibility with the polymer donor to induce a favorable blend ordering with small domain sizes and suitable phase separation compared to the INPIC-2F symmetric molecule. This facilitates an efficient charge generation and transport, inhibits charge-carrier recombination, and promotes valid charge extraction in IPT-2F-based devices.