Two novel oligomers boost the 1 cm² device to achieve a remarkable PCE exceeding 17% using a green solvent in open-air without post-treatment. In-depth in situ & ex situ studies elucidate the mechanisms of action of the oligomers. This work demonstrates effective guidelines for future manufacturing.

The interfacial solar steam generation (ISSG) system has garnered widespread attention in addressing the global freshwater scarcity issue. Enhancing the performance of the ISSG system relies on the development of highly efficient photothermal materials. We have developed a new platinum-based photothermal polymer, named PffBTPt, which shows excellent sunlight absorption capability through intermolecular and ligand-to-ligand charge transfer mechanisms investigated by DFT calculations. An effective and stable solar evaporator is successfully fabricated by depositing PffBTPt onto a polyurethane foam (PU) substrate. The surface temperature of PffBTPt-attached PU rapidly rises up to nearly its peak value of 66.4 °C within 1 minute under 1 sun due to effective nonradiative transitions, surpassing 36.5 °C of the PU. The solar evaporator exhibits a water evaporation efficiency of 85.6% and an evaporation rate of 1.57 kg m⁻² h⁻¹ under 1 sun, as well as achieves a 3–5 order of magnitude reduction in the concentrations of Ca²⁺, K⁺, Mg²⁺, and Na⁺ after desalination of seawater. In this study, the organometallic photothermal material is reported for the first time, demonstrating its significant potential in simultaneous clean water production and seawater desalination. This research also offers a fresh perspective on the molecular design aimed at creating effective organometallic photothermal polymers by integrating a suitable metal complex into the polymer backbone.

Quasi-layered all-polymer solar cells (QLA-PSCs) were fabricated based on wide bandgap polymer PM6 as a donor and narrow bandgap polymer PY-IT as an acceptor. A nonfullerene acceptor, L8-BO, is deliberately selected as a solid additive due to its similar chemical structure to the segment of polymer acceptor PY-IT. The power conversion efficiency (PCE) of the QLA-PSCs is increased from 16.14% to 17.74% by incorporating 2 wt% L8-BO into the PY-IT layer, benefiting from the synergistically increased short circuit current density (24.45 mA cm⁻²vs. 23.41 mA cm⁻²) and fill factor (76.38% vs. 72.60%). The contribution of L8-BO as a solid additive on the performance improvement of the QLA-PSCs can be summarized as follows: (i) it induces more ordered molecular orientation of PY-IT confirmed from GIWAXS; (ii) it enlarges the exciton diffusion length in the PY-IT layer and facilitates efficient hole transfer from PY-IT to PM6 as demonstrated by transient absorption; (iii) it increases the exciton dissociation interface as evidenced by the contact angle and photoluminescence of PM6/PY-IT without or with L8-BO. It should be highlighted that the 2000 h storage stability of the QLA-PSCs can be significantly improved, with PCE retention increasing from 85.1% to 90.2% of the initial value upon incorporating L8-BO as a solid additive. The effect of the universality of the nonfullerene acceptor as a solid additive on the performance improvement of QLA-PSCs can also be confirmed by the boosted PCE to 16.71% or 16.79% with Y6 or BO-4F as a solid additive. This work shows that a small molecular nonfullerene acceptor may induce a polymer acceptor molecular arrangement to further improve the performance of QLA-PSCs.