School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
Nano Lett. 2017 Apr 12;17(4):2496-2505. doi: 10.1021/acs.nanolett.7b00200. Epub 2017 Mar 15.
Compared to the conventional perovskite solar cells (PSCs) containing hole-transport materials (HTM), carbon materials based HTM-free PSCs (C-PSCs) have often suffered from inferior power conversion efficiencies (PCEs) arising at least partially from the inefficient hole extraction at the perovskite-carbon interface. Here, we show that boron (B) doping of multiwalled carbon nanotubes (B-MWNTs) electrodes are superior in enabling enhanced hole extraction and transport by increasing work function, carrier concentration, and conductivity of MWNTs. The C-PSCs prepared using the B-MWNTs as the counter electrodes to extract and transport hole carriers have achieved remarkably higher performances than that with the undoped MWNTs, with the resulting PCE being considerably improved from 10.70% (average of 9.58%) to 14.60% (average of 13.70%). Significantly, these cells show negligible hysteretic behavior. Moreover, by coating a thin layer of insulating aluminum oxide (AlO) on the mesoporous TiO film as a physical barrier to substantially reduce the charge losses, the PCE has been further pushed to 15.23% (average 14.20%). Finally, the impressive durability and stability of the prepared C-PSCs were also testified under various conditions, including long-term air exposure, heat treatment, and high humidity.
与含有空穴传输材料（HTM）的传统钙钛矿太阳能电池（PSCs）相比，基于碳材料的无 HTM 的 PSCs（C-PSCs）的功率转换效率（PCE）往往较低，这至少部分归因于钙钛矿-碳界面处空穴提取效率低下。在这里，我们表明，通过增加多壁碳纳米管（MWNTs）的功函数、载流子浓度和电导率，硼（B）掺杂 MWNTs 电极在增强空穴提取和输运方面具有优越性。使用 B-MWNTs 作为对电极来提取和传输空穴载流子的 C-PSCs 表现出显著更高的性能，与未掺杂的 MWNTs 相比，其 PCE 从 10.70%（平均值为 9.58%）显著提高到 14.60%（平均值为 13.70%）。值得注意的是，这些电池表现出可忽略的滞后行为。此外，通过在介孔 TiO2 薄膜上涂覆一层薄的绝缘氧化铝（AlO）作为物理阻挡层，可大大减少电荷损耗，从而进一步将 PCE 提高到 15.23%（平均值 14.20%）。最后，还在各种条件下对制备的 C-PSCs 的耐用性和稳定性进行了测试，包括长期暴露于空气中、热处理和高湿度。
