@article{taussig_ghasemi_han_kwansa_li_keene_woodward_yingling_malliaras_gomez_et al._2024, title={Electrostatic self-assembly yields a structurally stabilized PEDOT:PSS with efficient mixed transport and high-performance OECTs}, volume={7}, ISSN={["2590-2385"]}, DOI={10.1016/j.matt.2023.12.021}, abstractNote={<h2>Summary</h2> Organic electronics and organic electrochemical transistors (OECTs) are gaining importance for their potential to replicate complex biological processes of the human brain. Such devices require polymeric materials to efficiently transport and couple ionic and electronic charges in aqueous media, therefore demanding water-insoluble systems capable of efficient electronic and ionic conductions. This has created a fundamental stability-performance compromise for water-soluble conducting polymers such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), whereby stability has been achieved at the expense of electronic properties. Here, we demonstrate a breakthrough in structural stabilization of PEDOT:PSS through electrostatic self-assembly (ESA) that leads to the formation of an efficient mixed conductor in a hydrated state. Benefiting from the multiscale morphology control provided by ESA, PEDOT:PSS mixed conductors exhibit superior carrier mobility and high volumetric capacitance resulting in a state-of-the-art thin-film OECT figure of merit (<i>μC</i>∗ = 752.5 F/cmVs) in aqueous media, making this approach suitable for creating robust mixed conductors for bioelectronic applications and beyond.}, number={3}, journal={MATTER}, author={Taussig, Laine and Ghasemi, Masoud and Han, Sanggil and Kwansa, Albert L. and Li, Ruipeng and Keene, Scott T. and Woodward, Nathan and Yingling, Yaroslava G. and Malliaras, George G. and Gomez, Enrique D. and et al.}, year={2024}, month={Mar} }
 @article{ghasemi_guo_darabi_wang_wang_huang_lefler_taussig_chauhan_baucom_et al._2023, title={A multiscale ion diffusion framework sheds light on the diffusion-stability-hysteresis nexus in metal halide perovskites}, ISSN={["1476-4660"]}, DOI={10.1038/s41563-023-01488-2}, abstractNote={Stability and current-voltage hysteresis stand as major obstacles to the commercialization of metal halide perovskites. Both phenomena have been associated with ion migration, with anecdotal evidence that stable devices yield low hysteresis. However, the underlying mechanisms of the complex stability-hysteresis link remain elusive. Here we present a multiscale diffusion framework that describes vacancy-mediated halide diffusion in polycrystalline metal halide perovskites, differentiating fast grain boundary diffusivity from volume diffusivity that is two to four orders of magnitude slower. Our results reveal an inverse relationship between the activation energies of grain boundary and volume diffusions, such that stable metal halide perovskites exhibiting smaller volume diffusivities are associated with larger grain boundary diffusivities and reduced hysteresis. The elucidation of multiscale halide diffusion in metal halide perovskites reveals complex inner couplings between ion migration in the volume of grains versus grain boundaries, which in turn can predict the stability and hysteresis of metal halide perovskites, providing a clearer path to addressing the outstanding challenges of the field.}, journal={NATURE MATERIALS}, author={Ghasemi, Masoud and Guo, Boyu and Darabi, Kasra and Wang, Tonghui and Wang, Kai and Huang, Chiung-Wei and Lefler, Benjamin M. and Taussig, Laine and Chauhan, Mihirsinh and Baucom, Garrett and et al.}, year={2023}, month={Feb} }