Polymer thermoelectrics offer an inherently soft, cost-effective, and lightweight solution to convert ubiquitous heat sources into sustainable electricity. However, their realistic applications are hindered by insufficient performance and the scaling complexity. We introduce irregular hierarchical-porous thermoelectric polymers, featuring irregularly shaped and distributed pores with diameters that range from less than 10 nanometers to micrometers. This porous structure not only enhances multiple phonon-like scattering, achieving a 72% reduction in lattice thermal conductivity, but also unexpectedly improves charge transport through nanoconfinement-enhanced crystallization. The optimized film yields a benchmark figure-of-merit zT of 1.64 at 343 kelvin. Moreover, this method is compatible with easy-to-process spray-coating techniques.

The applications of non-fullerene acceptor Y6 with a new type of A₁-DA₂D-A₁ framework and its derivatives have increased the power conversion efficiency (PCE) of organic solar cells (OSCs) up to 19%. Researchers have made various modifications of the donor unit, central/terminal acceptor unit, and side alkyl chains of Y6 to study the influences on the photovoltaic properties of OSCs based on them. However, up to now, the effect of changes of terminal acceptor parts of Y6 on the photovoltaic properties is not very clear. In the present work, we have designed four new acceptors—Y6-NO₂, Y6-IN, Y6-ERHD, and Y6-CAO—with different terminal groups, which possess diverse electron-withdrawing ability. Computed results show that with the enhanced electron-withdrawing ability of the terminal group, the fundamental gaps become lower; thus, the wavelengths of the main absorption peaks of UV-Vis spectra red-shifts and total oscillator strength increase. Simultaneously, the electron mobility of Y6-NO₂, Y6-IN, and Y6-CAO is about six, four, and four times faster than that of Y6, respectively. Overall, Y6-NO₂ could be a potential NFA because of its longer intramolecular charge-transfer distance, stronger dipole moment, higher averaged ESP, enhanced spectrum, and faster electron mobility. This work provides a guideline for the future research on modification of Y6.

The electron affinity (EA) of OSCs and the ionization energy (IE) of dopant radicals (D˙s) are two molecular descriptors for the n-doping reaction with DMBI-H derivatives, and EA(OSC) − IE(D^·) > 1.0 eV is proposed as a criterion for efficient doping.