An efficient electron transport layer (ETL) plays a key role in promoting carrier separation and electron extraction in planar perovskite solar cells (PSCs). An effective composite ETL is fabricated using carboxylic-acid- and hydroxyl-rich red-carbon quantum dots (RCQs) to dope low-temperature solution-processed SnO2 , which dramatically increases its electron mobility by ≈20 times from 9.32 × 10-4 to 1.73 × 10-2 cm2 V-1 s-1 . The mobility achieved is one of the highest reported electron mobilities for modified SnO2 . Fabricated planar PSCs based on this novel SnO2 ETL demonstrate an outstanding improvement in efficiency from 19.15% for PSCs without RCQs up to 22.77% and have enhanced long-term stability against humidity, preserving over 95% of the initial efficiency after 1000 h under 40-60% humidity at 25 °C. These significant achievements are solely attributed to the excellent electron mobility of the novel ETL, which is also proven to help the passivation of traps/defects at the ETL/perovskite interface and to promote the formation of highly crystallized perovskite, with an enhanced phase purity and uniformity over a large area. These results demonstrate that inexpensive RCQs are simple but excellent additives for producing efficient ETLs in stable high-performance PSCs as well as other perovskite-based optoelectronics.

中文翻译：

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高效且稳定的钙钛矿太阳能电池具有增强的电子迁移率的红碳量子点掺杂的SnO2复合材料。

有效的电子传输层（ETL）在促进平面钙钛矿太阳能电池（PSC）中的载流子分离和电子提取中起着关键作用。使用富含羧酸和羟基的红色碳量子点（RCQ）掺杂低温固溶处理的SnO2，可以制得有效的复合ETL，该SnO2的电子迁移率从9.32×10-4大大提高了20倍左右，达到了1.73×10-2 cm2 V-1 s-1。获得的迁移率是改性SnO2报道的最高电子迁移率之一。基于这种新型SnO2 ETL的平面式PSC的效率显着提高，从无RCQ的PSC的19.15％提高到22.77％，并且具有增强的长期耐湿稳定性，在40-1000°C下保存1000小时后的初始效率超过95％ 25°C时60％湿度。这些重大成就完全归功于新型ETL的出色电子迁移率，这也被证明有助于钝化ETL /钙钛矿界面上的陷阱/缺陷，并促进高结晶钙钛矿的形成，并提高了相纯度和大面积均匀。这些结果表明，廉价的RCQ是简单而优良的添加剂，可用于在稳定的高性能PSC以及其他基于钙钛矿的光电产品中生产有效的ETL。