Despite the high efficiency of MAPbI₃ perovskite solar cells, the long term stability and degradation in humid atmosphere are issues that still needed to be addressed. In this work, magnesium iodide (MgI₂) was first successfully used as a dopant into MAPbI₃ perovskite prepared in humid air atmosphere. Mg doping decreased the valence band level, which was determined from photoelectron yield spectroscopy. Compared to the pristine MAPbI₃ perovskite film, the 1.0% Mg-doped perovskite film showed increased crystal grain size and formation of pinhole-free perovskite film. Performance of the solar cell was increased from 14.2% of the doping-free solar cell to 17.8% of 1.0% Mg-doped device. Moreover, 90% of the original power conversion efficiency was still retained after storage in 30–40% relative humidity for 600 h.

中文翻译：

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镁掺杂的MAPbI ₃钙钛矿层可增强潮湿空气中的光伏性能

尽管MAPbI ₃钙钛矿太阳能电池的效率很高，但在潮湿环境中的长期稳定性和退化仍然是需要解决的问题。在这项工作中，碘化镁（MgI ₂）首先成功地用作在潮湿空气环境中制备的MAPbI ₃钙钛矿中的掺杂剂。镁掺杂降低了价带能级，这是由光电子产率光谱法确定的。与原始MAPbI ₃相比钙钛矿薄膜中，掺有1.0％Mg的钙钛矿薄膜显示出增加的晶粒尺寸和无针孔钙钛矿薄膜的形成。太阳能电池的性能从无掺杂太阳能电池的14.2％提高到1.0％掺Mg的器件的17.8％。此外，在30-40％的相对湿度下存储600小时后，仍保留了90％的原始功率转换效率。