Growth of CH3NH3PbI3 cuboids with controlled size for high-efficiency perovskite solar cells
Growth of CH3NH3PbI3 cuboids with controlled size for high-efficiency perovskite solar cells
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DOI：
10.1038/nnano.2014.181
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发表时间：
2014-11-01
影响因子：
38.3
通讯作者：
Park, Nam-Gyu
中科院分区：
文献类型：
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作者：
Im, Jeong-Hyeok;Jang, In-Hyuk;Park, Nam-Gyu
具有亚微米厚的CH 3 NH3 PbI 3或CH 3 NH3 PbI 3-xClx活性层的Percent太阳能电池显示出高达15%的功率转换效率。然而，与性能最好的设备相比，平均效率低至12%，标准差（s.d.）较大。在这里，我们报告了平均效率超过16%，最佳效率为17%的钙钛矿太阳能电池。这是通过经由两步旋涂程序生长具有受控尺寸的CH 3 NH3 PbI 3立方体来实现的。旋涂不同浓度的CH_3NH_3I溶液后旋涂PbI_2，发现CH_3NH_3PbI_3的立方体尺寸强烈依赖于CH_3NH_3I的浓度。光捕获效率和电荷载体提取显着影响的长方体的大小。在模拟一个太阳光照下，平均效率为16.4%（s.d.）。+/- 0.35）、16.3%（s.d. +/- 0.44）和13.5%（s.d. +/- 0.34）分别从浓度为0.038 M、0.050 M和0.063 M的CH 3 NH3 I溶液中获得。通过控制CH 3 NH3 PbI 3晶体生长过程中晶体的尺寸，我们获得了最佳的光电转换效率17.01%，光电流密度为21.64mA cm（-2），开路光电压为1.056V，填充因子为0.741。
Perovskite solar cells with submicrometre-thick CH3NH3PbI3 or CH3NH3PbI3-xClx active layers show a power conversion efficiency as high as 15%. However, compared to the best-performing device, the average efficiency was as low as 12%, with a large standard deviation (s.d.). Here, we report perovskite solar cells with an average efficiency exceeding 16% and best efficiency of 17%. This was enabled by the growth of CH3NH3PbI3 cuboids with a controlled size via a two-step spin-coating procedure. Spin-coating of a solution of CH3NH3I with different concentrations follows the spin-coating of PbI2, and the cuboid size of CH3NH3PbI3 is found to strongly depend on the concentration of CH3NH3I. Light-harvesting efficiency and charge-carrier extraction are significantly affected by the cuboid size. Under simulated one-sun illumination, average efficiencies of 16.4% (s.d. +/- 0.35), 16.3% (s.d. +/- 0.44) and 13.5% (s.d. +/- 0.34) are obtained from solutions of CH3NH3I with concentrations of 0.038 M, 0.050 M and 0.063 M, respectively. By controlling the size of the cuboids of CH3NH3PbI3 during their growth, we achieved the best efficiency of 17.01% with a photocurrent density of 21.64 mA cm(-2), open-circuit photovoltage of 1.056 V and fill factor of 0.741.