Perovskite solar cell, which is prepared by using the organic-inorganic hybrid halide CH3NH3PbX3 (X = I, Cl and Br), receives widespread attention because of its solution processability and high photon-to-electron conversion effi-ciency. The highest reported photon-to-electron conversion efficiency is that using CH3NH3PbI(3−x)Clx as an absorber. It is reported that the diffusion length is greater than 1 micrometer in this mixed halide perovskite. The method most commonly used in preparing CH3NH3PbI(3−x)Clx film is the one-step pyrolysis method, which has a complex reaction mechanism. In this paper, we review the work about CH3NH3PbI(3−x)Clx perovskite, in which emphasis is put on the importance of the preparation process, and analyze the role of CH3NH3I in the one-step pyrolysis method for fabricating the CH3NH3PbI(3−x)Clxperovskite layer. Scanning electron microscope images show that CH3NH3I can improve the cov-erage and crystallinity of the perovskite layer for precursors in low CH3NH3I concentrations (CH3NH3I/PbCl2=2.0 and 2.5). For precursors in high CH3NH3I concentrations (CH3NH3I/PbCl2=2.75 and 3), this change is not obvious. X-ray photoelectron spectroscopy confirms the change of coverage, and indicates that the content of Cl in CH3NH3PbI(3−x)Clx will be less than 5% for precursors with high CH3NH3I concentrations (CH3NH3I/PbCl2 >2.5). Perovskite solar cells based on CH3NH3PbI(3−x)Clx with different Cl dopant concentrations are studied by photoelectric measurements. Pho-tocurrent density-photovoltage curves show that the performance of the devices increases with the increase of CH3NH3I concentration in precursors. And the incident-photon-to-current conversion efficiency (IPCE) measurements indicate that the devices fabricated by using precursors with high CH3NH3I concentration have a relatively high external quan-tum efficiency. These results imply that only CH3NH3PbI(3−x)Clx with very low Cl dopant concentration will be effective material for photovoltaic application. To further understand the difference between these devices during working con-dition, transient photovoltage/photocurrent measurements are carried out to investigate the carrier dynamics in the device. Transient photovoltage decay curves indicate that high Cl dopant concentration may decrease the photoelectron lifetime in CH3NH3PbI(3−x)Clx, and results in a relative low open-circuit photovoltage in the corresponding photovoltaic devices. The charge transport time in the devices of various Cl concentrations are studied by transient photocurrent decay method. CH3NH3PbI(3−x)Clxwith low Cl dopant concentration has relative short transport time, which can avoid the recombination process and increase the charge collection efficiency.%利用具有钙钛矿结构的有机-无机杂化卤化物制备的太阳能电池，由于具有溶液可加工性和高光电转换效率，受到了广泛关注.在目前报道的最高光电转换效率的器件中，采用了CH3NH3PbI(3−x)Clx碘氯混合钙钛矿作为吸光层，据报道在这种材料中光电子的扩散长度可以超过1µm.本文综述了在CH3NH3PbI(3−x)Clx方面现有的研究工作，指出了薄膜制备条件的重要性，并研究了CH3NH3I在PbCl2/CH3NH3I热解法制备CH3NH3PbI(3−x)Clx吸光层中的作用.扫描电子显微镜研究表明CH3NH3I加入量为PbCl2的2倍到2.75倍时， CH3NH3I加入量的增加可以提高CH3NH3PbI(3−x)Clx吸光层的覆盖度和结晶度， CH3NH3I加入量进一步增加到3倍时，形貌变化不大. X射线光电子能谱的数据证实了CH3NH3I加入量对覆盖度的影响，并显示在CH3NH3I加入量大于PbCl2的2.5倍以后， CH3NH3PbI(3−x)Clx中氯的掺入量急剧下降.光电测试表明器件性能随CH3 NH3 I加入量增加而增加，在CH3 NH3 I/PbCl2为3/1时达到最高，加入量略小于3/1对性能影响不大.
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