A systematic study is conducted to compare the performances and stability of active layers employing a high performance electron donor (PBDB‐T) combined with state‐of‐the‐art fullerene (PC71BM), nonfullerene (ITIC), and polymer (N2200) electron acceptors. The impact of the chemical nature of the acceptor on the durability of organic solar cells (OSCs) is elucidated by monitoring their photovoltaic performances under light exposure or dark conditions in the presence of oxygen. PC71BM molecules exhibit a higher resistance toward oxidation compared to nonfullerene acceptors. Unencapsulated PBDB‐T:PC71BM OSCs display relatively stable performances at room temperature when stored in air for 3 months. However, when exposed to temperatures above 80 °C, their active materials demix causing notable reductions in the short‐circuit densities. Such detrimental demixing can also be seen for PBDB‐T:ITIC active layers above 120 °C. Although N2200 chains irreversibly degrade when exposed to air, thermally induced demixing does not occur in PBDB‐T:N2200 active layers annealed up to 200 °C. In summary, fullerene OSCs may be the best currently available choice for unencapsulated room temperature applications but if oxidation of the polymer acceptors can be avoided, all polymer active layers should enable the fabrication of highly durable OSCs with lifetimes matching the requirements for OSC commercialization.

Methods are described for the preparation of cobalt(II) deuteroporphyrin and cobalt(II) tetrakis(p-sulfonatophenyl)porphine anchored on alumina beads coated with polyaminesulfone-A. Wavelength dispersive X-ray microanalysis showed that the cobalt(II) porphine distributes within the catalyst outer surface layer of ca. 100 μm depth. The catalysts are highly active for the cycloreversion of quadricyclane to norbornadiene. A detailed kinetics of the isomerization using an isothermal recycle reactor gave a rate expression of Langmuir–Hinshelwood type. The catalysts gradually lose their activity, which can be regenerated completely by heating the catalysts at 200 °C in vacuo.

The power conversion efficiency (PCE) of organic solar cells (OSCs) has been gradually increasing over the past years, but these emerging photovoltaic devices still suffer from relatively short lifetimes. To promote circular economy and reduce costly electronic materials wastes, we explore the possibility of recycling durable zinc oxide coated indium tin oxide (ITO/ZnO) from nonfullerene OSCs through sequential ultrasonication in a series of solvents followed by thermal annealing. With the adequate cleaning sequence, the recycled ITO/ZnO substrates produce PCEs of 8.65%, a value comparable to the PCEs obtained with freshly prepared substrates (8.73%). Our results also indicate that isopropanol gradually removes the zinc oxide layer and should thus be avoided when attempting multiple successive recycling of the same substrate. ITO/ZnO substrates recycled 10 times with and without isopropanol yield PCEs of 5.14% and 7.93%, respectively. By optimizing the recycling procedure, we introduce a simple strategy to considerably increase the lifecycle of transparent electrode substrates employed in organic electronic devices and decrease the amount of wastes from the electronic industry.

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