Despite significant advancements in improving the power-conversion efficiency (PCE) of exceeding 27% in perovskite solar cells (PSCs), the insufficient operational stability of PSCs under illumination remains a critical challenge, posing a major obstacle to their commercial viability. This paper proposes a feasible hindered amine stabilization strategy (HASS) by using a hindered amine light stabilizer for grain and surface modulation of perovskite, thereby blocking the internal and external degradation pathways of perovskite. Its piperidine ring is easily oxidized to form Nitrogen monoxide (N–O•) radicals after absorbing light energy in an aerobic environment. The free superoxide radical (O 2 • − ) radicals react with perovskite and H + in the decomposition products of perovskite, thereby improving the light stability of the device. In addition, the contained triazine and morpholine functional groups can coordinate with Pb 2+ , thereby reducing the interface defects and inhibiting the non-radiative recombination. The HASS-modulated PSC could reach the champion PCE of 26.74% (certified 26.56%), which is remarkable for inverted PSCs prepared under ambient conditions. Further, the unencapsulated device could maintain 95.4% of its initial PCE after more than 1000 hours of aging at maximum power point tracking.
Fabricating an effective synergism between the condensed phase (char-forming) and the gas phase (free-radical quenching) is recently considered to be a very promising way to prepare high-efficient intumescent flame retardants . In this work, a novel hindered amine phosphorous-nitrogen macromolecular charring agent (HAPN) with free-radical quenching capability was synthesized and characterized. Then it was combined with ammonium polyphosphate (APP) to flame-retard polypropylene (PP). The flame retardancy and thermal stability of PP/HAPN/APP mixtures were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetric test (CCT) and thermogravimetric analysis (TGA). When the content of HAPN/APP was 25 wt%, PP/HAPN/APP could self-extinguish at 36 s after igniting in the oxygen concentration of 29.5% and achieve a UL-94 V-0 rating. Meanwhile, the peak heat release rate (PHRR), total heat release rate (THR), average heat release rate (AV-HRR) and average mass loss rate (AV-MLR) were significantly decreased. The flame retardant mechanism of HAPN/APP was explored and the results revealed that there was an effective synergism between the condensed phase and the gas phase during the combustion. In the condensed phase, HAPN could make PP involve into the char-forming reaction to promote the formation of compact and firm intumescent char layer. Simultaneously, the nitroxyl radical generated by HAPN could effectively restrain and even extinguish the flame in the gas phase by quenching the active free-radicals.
危险品化学品经营许可证（带存储）