Nanocrystalline Rutile Electron Extraction Layer Enables Low-Temperature Solution Processed Perovskite Photovoltaics with 13.7% Efficiency
Nanocrystalline Rutile Electron Extraction Layer Enables Low-Temperature Solution Processed Perovskite Photovoltaics with 13.7% Efficiency
复制标题
DOI：
10.1021/nl500399m
复制
发表时间：
2014-05-01
期刊：
影响因子：
10.8
通讯作者：
Graetzel, Michael
中科院分区：
文献类型：
--
作者：
Yella, Aswani;Heiniger, Leo-Philipp;Graetzel, Michael
我们展示了基于 TiO2/CH3NH3PbI3 的太阳能电池的低温（70 摄氏度）溶液加工，其功率转换效率 (PCE) 高达 13.7%。除了高效率之外，使用这种低温化学浴沉积方法还实现了 1110 mV 的惊人高开路电位 (V-OC)。据我们所知，这是迄今为止溶液处理的 TiO2/CH3NH3PbI3 太阳能电池的最高 V-OC 值。我们通过 TiCl4 在 70 摄氏度下水解，在掺氟氧化锡 (FTO) 导电玻璃基板上沉积了纳米晶 TiO2（金红石）空穴阻挡层，与光敏 CH3NH3PbI3 薄膜形成电子选择性接触。我们发现纳米晶金红石 TiO2 比通过高温旋涂 TiCl4 制备的平面 TiO2（锐钛矿）薄膜具有更好的性能，其 PCE 低得多，为 3.7%。我们将此归因于纳米晶金红石 TiO2 和 CH3NH3PbI3 层之间形成了大界面面积的紧密连接，这比平面锐钛矿薄膜在提取光生电子方面更有效。由于太阳能电池的完整制造是在 100 摄氏度以下进行的，因此该方法可以轻松扩展到塑料基板。
We demonstrate low-temperature (70 degrees C) solution processing of TiO2/CH3NH3PbI3 based solar cells, resulting in impressive power conversion efficiency (PCE) of 13.7%. Along with the high efficiency, a strikingly high open circuit potential (V-OC) of 1110 mV was realized using this low-temperature chemical bath deposition approach. To the best of our knowledge, this is so far the highest V-OC value for solution-processed TiO2/CH3NH3PbI3 solar cells. We deposited a nanocrystalline TiO2 (rutile) hole-blocking layer on a fluorine-doped tin oxide (FTO) conducting glass substrate via hydrolysis of TiCl4 at 70 degrees C, forming the electron selective contact with the photoactive CH3NH3PbI3 film. We find that the nanocrystalline rutile TiO2 achieves a much better performance than a planar TiO2 (anatase) film prepared by high-temperature spin coating of TiCl4, which produces a much lower PCE of 3.7%. We attribute this to the formation of an intimate junction of large interfacial area between the nanocrystalline rutile TiO2 and the CH3NH3PbI3 layer, which is much more effective in extracting photogenerated electrons than the planar anatase film. Since the complete fabrication of the solar cell is carried out below 100 degrees C, this method can be easily extended to plastic substrates.