Hole-transport material-free perovskite solar cells were prepared by utilizing a spin-coating method. To optimize the dropping conditions of the toluene as an antisolvent in the nitrogen atmosphere, the CH₃NH₃PbI₃/TiO₂/fluorine-doped tin oxide (FTO)/glass specimen consisted of a high-density tissue, and crystal faults such as voids and cracks were not observed on its surface. By controlling the thickness of the mesoporous TiO₂ layer with the rotation speed (x) of a spin coater, it was speculated that the thicker mesoporous TiO₂ layer enables not only an efficient electron extraction from the CH₃NH₃PbI₃ perovskite layer but also a smooth transition of electrons to the FTO electrode. Moreover, the precursor solution for CH₃NH₃PbI₃ perovskite crystals was optimized for its molar concentration (y). The energy conversion efficiency (η) gradually increased from η = 5.8% to 9.6% with an increase in y to 2.6 M above which it decreased. The reason to obtain a superior energy conversion efficiency is so that the larger interface between the mesoporous TiO₂ and perovskite layers is able to extract photoexcited electrons effectively. The above facts show for that the perovskite solar cells that have a larger area are synthesized with good reproducibility.

中文翻译：

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光激发电子在无空穴传输的钙钛矿太阳能电池中的行为

利用旋涂法制备了无空穴传输材料的钙钛矿型太阳能电池。为了优化甲苯作为抗溶剂在氮气气氛中的滴落条件，CH ₃ NH ₃ PbI ₃ / TiO ₂ /氟掺杂的氧化锡（FTO）/玻璃样品由高密度组织和晶体缺陷等组成。因为在其表面未观察到空隙和裂缝。据推测，通过利用旋涂机的旋转速度（x）控制介孔TiO ₂层的厚度，较厚的介孔TiO ₂层不仅能够有效地从CH ₃ NH ₃ PbI提取电子。₃钙钛矿层还可以使电子平稳过渡到FTO电极。此外，针对CH ₃ NH ₃ PbI ₃钙钛矿晶体的前体溶液的摩尔浓度（y）进行了优化。能量转换效率（η）从η  = 5.8％逐渐增加到9.6％，随着y的增加到2.6 M，在此之上它降低了。获得优异的能量转换效率的原因是，介孔TiO ₂之间的界面更大钙钛矿层能够有效地提取光激发电子。上述事实表明，具有良好再现性的具有较大面积的钙钛矿太阳能电池被合成。