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Conjugated polymers are at the heart of numerous current and emerging technologies. Doping, a process by which charge carriers are introduced, is crucial to their functionality and performance. Despite significant historical context and the exploration of a broad chemical space, doping processes that are activated by formation of a ground-state charge-transfer complex (GS-CTC), which is mediated by the supramolecular hybridization between the frontier molecular orbitals of distinct molecular species, remain poorly understood. There are no clear demonstrations of this phenomena in contemporary donor–acceptor (DA) conjugated polymers (CP). Here, using diketopyrrolopyrrole-based donor–acceptor semiconducting polymers and a -conjugated penta-t-butylpentacyanopentabenzo[25]annulene “cyanostar” macrocycle, we demonstrate the first examples of features that control GS-CTC formation in contemporary DA CP frameworks. Using complementary experimental techniques and theory, we articulate how subtle molecular, electronic, and solid-state features impact supramolecular hybridization of the frontier molecular orbitals and impact the resultant (opto)electronic, magnetic, and transport properties. These studies demonstrate that subtle effects arising from the admixture between distinct -conjugated materials can have dramatic outcomes on properties and performance through modification of the density of states (DOS). These results will enable completely new design rules for organic semiconductors with precise property control. 

A point-of-use electrochemical phosphate sensor is achieved with electrodeposited mixed-valence molybdenum oxide on flexible electrodes, enabling selective detection in complex aqueous environments. 

Low-energy, infrared (IR) photodetection forms the foundation for industrial, scientific, energy, medical, and defense applications. State-of-the-art technologies suffer from limited modularity, intrinsic fragility, high-power consumption, require cooling, and are largely incompatible with integrated circuit technologies. Conjugated polymers offer low-cost and scalable fabrication, solution processability, room temperature operation, and other attributes that are not available using current technologies. Here, we demonstrate new materials and device paradigms that enable an understanding of emergent light-matter interactions and optical to electrical transduction of IR light. Photodiodes show a response to 2.0 μm, while photoconductors respond across the near- to long-wave infrared (1–14 µm). Fundamental investigations of polymer and device physics have resulted in improving performance to levels now matching commercial inorganic detectors. This is the longest wavelength light detected for organic materials and the performance exceeds graphene at longer wavelengths. Photoconductors outperform their inorganic counterparts and operate at room temperature with higher response speeds. 

Structural supercapacitors reach high performance with a gradient electrolyte and redox polymer electrodes.