In this work, we report the benefits of incorporating phenethylammonium cation (PEA⁺) into (HC(NH₂)₂PbI₃)_0.85(CH₃NH₃PbBr₃)_0.15 perovskite for the first time. After adding small amounts of PEA cation (<10%), the perovskite film morphology is changed but, most importantly, grain boundaries are passivated. This is supported by Kelvin Probe Force Microscopy (KPFM). The passivation results in the increase in photoluminescence intensity and carrier lifetimes of test structures and open-circuit voltages (V_OC) of the devices as long as the addition of PEA⁺ is ≤4.5%. The presence of higher-band-gap quasi-2D PEA incorporated perovskite is responsible for the grain boundary passivation, and the quasi-2D perovskites are also found to be concentrated near the TiO₂ layer, revealed by PL spectroscopy. Results of moisture exposure tests show that PEA⁺ incorporation is effective in slowing down the degradation of unencapsulated devices compared to the control devices without PEA⁺. These findings provide insights into the operation of perovskite solar cells when large cations are incorporated.

中文翻译：

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甲铵-甲基铵卤化钙钛矿型太阳能电池中苯乙铵对晶界的钝化作用

在这项工作中，我们首次报告了将苯乙铵阳离子（PEA ⁺）掺入（HC（NH ₂）₂ PbI ₃）_0.85（CH ₃ NH ₃ PbBr ₃）_0.15钙钛矿中的好处。加入少量的PEA阳离子（<10％）后，钙钛矿膜的形态发生了变化，但最重要的是，晶界被钝化了。开尔文探针力显微镜（KPFM）对此提供了支持。只要添加PEA ⁺，钝化将导致测试结构的光致发光强度和载流子寿命以及器件的开路电压（V _OC）的增加。≤4.5％。通过PL光谱法发现，掺入较高带隙的准2D PEA的钙钛矿的存在导致晶界钝化，并且还发现准2D钙钛矿集中在TiO ₂层附近。水分暴露测试的结果表明，与不含PEA ⁺的对照装置相比，PEA ^+的掺入可有效减缓未封装装置的降解。这些发现为掺入大阳离子的钙钛矿太阳能电池的运行提供了见识。