Doping of organic materials has been studied intensively to adjust their electronic structures, and can briefly be described as exposure of electron accepting compounds to electron donating hosts (vice versa) to carry out electron transfer in between.[1] The process called p-doping if the electron is transferred from host to dopant, and n-doping for the other way around. Among both, p-doping is more common due to the feasibility of electronic levels of p-dopants, and also the less oxygen sensitivity of their formed pair. The most significant observation after the doping process is reduced resistivity due to the charged interfaces, which leads to higher electronic conductivities.

Porous polymers are interesting compounds for organic electronics thanks to their high dimensional and hydrothermally stable porous backbone possessing high accessible surface areas.[2,3] Particularly, the porosity can be interesting for doping since the pores are already adequately open spaces to welcome the dopants. Indeed, such property make them more intriguing for n-doping since the oxygen interference in those empty voids is less when compared to traditional (1D and non-porous) polymers. Moreover, the confinement effect is also a driving force to utilize n-doping even though the electronic levels of the dopants (HOMO) and host (LUMO) are not very feasible.[4,5]

In this presentation, doping of n-type porous polymers will be presented. Specifically, results based on a porous polymer bearing phenazine moieties as the electron acceptor units versus the tetrathiafulvalene (TTF) dopant will be shown.[6] Full physical and spectral characterizations (gas sorption (surface area detection), elemental analysis, NMR, FT-IR, UV-VIS) before and after doping will be discussed. Computational approaches, time-resolved fluorescence and transient absorption spectroscopies to identify the nature of charged pair (charge-transfer complex) will be introduced. Moreover, comparison of the photoelectrochemical measurements before and after doping will be shown to highlight the effect of doping on the photocurrents. Furthermore, some recent results from novel n-type porous polymers and their charge-transfer complexes with TTF can be added to the conclusion to support the wide-range applicability of TTF doping for adjusting the photophysical and electronic properties of n-type materials.