Effect of relative humidity on crystal growth, device performance and hysteresis in planar heterojunction perovskite solar cells
Effect of relative humidity on crystal growth, device performance and hysteresis in planar heterojunction perovskite solar cells
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DOI：
10.1039/c5nr04179a
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发表时间：
2016-01-01
期刊：
影响因子：
6.7
通讯作者：
Kelly, Timothy L.
中科院分区：
文献类型：
--
作者：
Gangishetty, Mahesh K.;Scott, Robert W. J.;Kelly, Timothy L.
由于有机铅卤化物钙钛矿的吸湿性，湿度是影响钙钛矿太阳能电池效率和寿命的最重要因素之一。虽然湿度对器件性能有长期的不利影响，但它在钙钛矿晶体的初始生长过程中也起着关键作用。在这里，我们证明了大气相对湿度（RH）通过顺序沉积技术在钙钛矿薄膜的形成过程中起着关键作用。我们的研究结果表明，RH结晶过程中有很大的影响，因此对设备的性能。SEM和pXRD分析表明，随着湿度的增加，微晶尺寸增加。在低RH下，观察到它们之间具有大间隙的小立方微晶的形成。这些空隙的存在不利地影响器件性能并导致器件中的显著滞后。在较高的RH下，钙钛矿晶体的尺寸较大，微晶之间具有更好的连接性。这产生了具有低滞后的高效平面异质结太阳能电池。通过在电池制造过程中仔细控制RH，使用P3HT作为空穴传输材料达到高达12.2%的效率。
Due to the hygroscopic nature of organolead halide perovskites, humidity is one of the most important factors affecting the efficiency and longevity of perovskite solar cells. Although humidity has a long term detrimental effect on device performance, it also plays a key role during the initial growth of perovskite crystals. Here we demonstrate that atmospheric relative humidity (RH) plays a key role during the formation of perovskite thin films via the sequential deposition technique. Our results indicate that the RH has a substantial impact on the crystallization process, and hence on device performance. SEM and pXRD analysis show an increase in crystallite size with increasing humidity. At low RH, the formation of small cubic crystallites with large gaps between them is observed. The presence of these voids adversely affects device performance and leads to substantial hysteresis in the device. At higher RH, the perovskite crystals are larger in size, with better connectivity between the crystallites. This produced efficient planar hetero-junction solar cells with low hysteresis. By careful control of the RH during the cell fabrication process, efficiencies of up to 12.2% are reached using P3HT as the hole-transport material.