TiO₂ is a widely used electron transport layer for high efficiency perovskite solar cells. However, many intrinsic shortcomings seriously deteriorate the devices performance. Herein, we demonstrate a facile and effective approach to improve the photovoltaic performance by passivating the TiO₂ mesoporous layer with a nanoscale dispersed 12-tungstophosphoric heteropolyacid (H₃PW₁₂O₄₀·nH₂O). Due to the strong interaction between H₃PW₁₂O₄₀·nH₂O and TiO₂, the passivated TiO₂ mesoporous electron transport layer (hereafter denoted as PW₁₂/TiO₂) with an optimal weight ratio shows a more uniform coverage on the underlying substrate in comparison with the bare TiO₂. Furthermore, the resulted PW₁₂/TiO₂ also shows an obviously improved conductivity and significantly increased photoluminescence quenching for the perovskite emission. Thereby, this strategy leads to an apparently improved photovoltaic performance of perovskite solar cells with power conversion efficiency enhancement from 15.05% to 18.20%. In conclusion, our present study provides an effective approach for further improving the performance of perovskite solar cells by passivating the mesoporous electron transport layer with the well-known heteropolyacids.

TiO ₂是用于高效钙钛矿太阳能电池的广泛使用的电子传输层。但是，许多固有的缺点严重降低了设备的性能。本文中，我们展示了一种通过用纳米级分散的12钨磷杂多酸（H ₃ PW ₁₂ O ₄₀ ·nH ₂ O）钝化TiO ₂介孔层来提高光伏性能的简便有效的方法。由于H ₃ PW ₁₂ O ₄₀ ·nH ₂ O与TiO ₂之间的强相互作用，钝化的TiO ₂介孔电子传输层（以下称为PW与裸露的TiO ₂相比，具有最佳重量比的₁₂ / TiO ₂）在下层基材上显示出更均匀的覆盖率。此外，所得的PW ₁₂ / TiO ₂还显示出明显改善的电导率，并显着增加了钙钛矿发射的光致发光猝灭。因此，该策略导致钙钛矿太阳能电池的光伏性能得到明显改善，功率转换效率从15.05％提高到18.20％。总之，我们的研究提供了一种有效的方法，可以通过用众所周知的杂多酸钝化介孔电子传输层来进一步提高钙钛矿型太阳能电池的性能。