Interface defects can generate serious nonradiative recombination in perovskite solar cells (PSCs) and need to be restrained for further optimization of device performance. Herein, common and easily available 2D MoS₂ nanosheets prepared by a ball-milled method are demonstrated. The obtained MoS₂ has bigger specific surface area and narrower pore distribution, inducing more water to be trapped on the surface or in pores of MoS₂. With annealing, the locally absorbed water can be desorbed, and much more Mo atoms at the outermost surface layers could bond with oxygen to repair the uncoordinated Mo at edge sites for more ordered Mo—S—Mo bonds, which can weaken the catalytic activity of MoS₂ to stabilize the heterojunction interface of hole transport layer (HTL)/perovskite. When it is used as the passivation layer between HTL and perovskite, the Mo²⁺–Mo⁴⁺ ion pair can promote electron transfer from Pb^° to I^°, suppressing the deep defects at this interface near the perovskite side. Meanwhile, MoS₂ can passivate the surface (or grain boundaries) defects through the bond of Mo—I or Pb—O. The resultant PSCs give a champion efficiency of 22.39% with MoS₂ treatment, thus enabling the decorated devices with excellent long-term stability.

中文翻译：

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用于有效界面钝化的简单球磨硫化钼​​纳米片具有自修复功能以获得高性能钙钛矿太阳能电池

界面缺陷会在钙钛矿太阳能电池（PSC）中产生严重的非辐射复合，需要加以抑制以进一步优化器件性能。本文展示了通过球磨法制备的常见且容易获得的二维 MoS _{2纳米片。}得到的MoS ₂具有更大的比表面积和更窄的孔分布，导致更多的水被捕获在MoS ₂的表面或孔中。通过退火，局部吸附的水可以被解吸，最外层表面更多的Mo原子可以与氧结合，修复边缘位置不配位的Mo，形成更有序的Mo-S-Mo键，从而削弱催化剂的催化活性。_二硫化钼稳定空穴传输层（HTL）/钙钛矿的异质结界面。当用作HTL和钙钛矿之间的钝化层时，Mo ²⁺ -Mo ⁴⁺离子对可以促进电子从Pb ^°向I ^°转移，抑制了该界面靠近钙钛矿侧的深缺陷。同时，MoS ₂可以通过Mo-I或Pb-O键钝化表面（或晶界）缺陷。得到的 PSC 采用 MoS ₂处理后的最高效率为 22.39%，从而使装饰设备具有出色的长期稳定性。