n‐Type‐doped polymers are key elements to fabricate all‐polymer thermoelectric generators but they are challenging to produce. Herein, a new strategy is proposed, which is based on polarity switching upon doping of a donor–acceptor (D–A) copolymer based on diketopyrrolopyrrol (DPP) and quintethiophene (5T) with FeCl3. Polarity switching from p‐type to n‐type is observed upon increasing the doping concentration of FeCl3. An analysis based on nonmonotonic density of states is proposed, which accounts for the main experimental trends and demonstrates that the polarity switch is governed by the electronic band filling that is determined by the dopant concentration. The influence of the curvature of the density of states is in addition discussed and a complete description of the doping induced transport regimes is proposed. This polarity switching depends on the molecular weight Mn of the polymer and shifts to higher FeCl3 concentrations with increasing Mn. This behavior is attributed to the change of the width of the density of states with Mn. The combination of polarity switching and alignment is a means to produce n‐type‐like oriented and conducting polymers with enhanced power factors up to 10 µW K−2 m−1 along the chain direction.

Finding the middle ground: A 1:1 host–guest complex consisting of a hexa‐peri‐hexabenzocoronene molecule sitting in the middle of the free cavity of a giant π‐conjugated carbazole macrocycle has been obtained (see STM image). The complex has been prepared by physisorption of a monolayer of macrocycles followed by gas‐phase deposition of graphene molecules by pulsed laser deposition.

Organic electronics is one of the hottest and most exciting research topics today. However, its performance still lags behind that of inorganic‐based electronics. This Progress Report demonstrates that by controlling the complexity of organic molecules at the molecular and at the supramolecular level as well as by choosing suitable processing techniques, the desired function for applications in electronics can be achieved. Our main focus is on polyphenylene‐based nanomaterials, versatile organic molecules that allow access to novel intricate materials. We emphasize the molecular complexity as well as the supramolecular organization and the interfacing of novel organic materials as key guidelines.

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