Heteroatom-doped graphene materials have been intensely studied as active electrodes in energy storage devices. Here, we demonstrate that boron-doped porous graphene can be prepared in ambient air using a facile laser induction process from boric acid containing polyimide sheets. At the same time, active electrodes can be patterned for flexible microsupercapacitors. As a result of boron doping, the highest areal capacitance of as-prepared devices reaches 16.5 mF/cm(2), 3 times higher than nondoped devices, with concomitant energy density increases of 5-10 times at various power densities. The superb cyclability and mechanical flexibility of the device are well-maintained, showing great potential for future microelectronics made from this boron-doped laser-induced graphene material.

Graphite intercalation compounds (GIC) possess a broad range of unique properties that are not specific to the parent materials. While the stage transition, changing the number of graphene layers sandwiched between the two layers of intercalant, is fundamentally important and has been theoretically addressed, experimental studies revealed only macroscopic parameters. On the microscale, the phenomenon remains elusive up to the present day. Here we monitor directly in real time the stage transitions using a combination of optical microscopy and Raman spectroscopy. These direct observations yield several mechanistic conclusions. While we obtained strong experimental evidence in support of the Daumas-Herold theory, we find that the conventional interpretation of stage transitions as sliding of the existing intercalant domains does not sufficiently capture the actual phenomena. The entire GIC structure transforms considerably during the stage transition. Among other observations, massive wavefront-like perturbations occur on the graphite surface, which we term the tidal wave effect.

Organic electrochemical transistors (OECTs) show great promise for flexible, low‐cost, and low‐voltage sensors for aqueous solutions. The majority of OECT devices are made using the polymer blend poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), in which PEDOT is intrinsically doped due to inclusion of PSS. Because of this intrinsic doping, PEDOT:PSS OECTs generally operate in depletion mode, which results in a higher power consumption and limits stability. Here, a straightforward method to de‐dope PEDOT:PSS using commercially available amine‐based molecular de‐dopants to achieve stable enhancement‐mode OECTs is presented. The enhancement‐mode OECTs show mobilities near that of pristine PEDOT:PSS (≈2 cm2 V−1 s−1) with stable operation over 1000 on/off cycles. The electron and proton exchange among PEDOT, PSS, and the molecular de‐dopants are characterized to reveal the underlying chemical mechanism of the threshold voltage shift to negative voltages. Finally, the effect of the de‐doping on the microstructure of the spin‐cast PEDOT:PSS films is investigated.

High mobility ambipolor organic thin-film transistors based on an ultralow bandgap polymer are presented together with their morphological and optical properties. Hole and electron mobilities of this polymer are of 1.0 cm(2) V(-1) s(-1) and 0.7 cm(2) V(-1) s(-1), respectively. The inverter based on two identical ambipolar transistors exhibits a gain around 35.

A family of four new DA polymers, in which the acceptor moiety benzobisthiadiazole was paired with four different donor moieties, has been synthesized. Surpri-singly, all members of the family exhibit balanced ambipolar behavior, despite polymer to polymer mobilities varying from 10(-4) cm(2) V(-1) s(-1) to 10(-1) cm(2) V(-1) s(-1). Applications in single component CMOS integrated circuits are envisioned.