Organometal halide perovskite semiconductors could potentially be used to create field-effect transistors (FETs) with high carrier mobilities. However, the performance of these transistors is currently limited by the migration of ionic surface defects. Here, we show that a surface cleaning and passivation technique, which is based on a sequence of three solution-based steps, can reduce the concentration of ionic surface defects in halide-based perovskites without perturbing the crystal lattice. The approach consists of an initial cleaning step using a polar/nonpolar solvent, a healing step to remove surface organic halide vacancies and a second cleaning step. The surface treatment is shown to restore clean, near hysteresis-free transistor operation, even if the perovskite films are formed under non-optimized conditions, and can improve room-temperature FET mobility by two to three orders of magnitude compared to untreated films. Our methylammonium lead iodide (MAPbI₃) FETs exhibit high n- and p-type mobilities of 3.0 cm² V⁻¹ s⁻¹ and 1.8 cm² V⁻¹ s⁻¹, respectively, at 300 K, and higher values (9.2 cm² V⁻¹ s⁻¹; n-type) at 80 K. We also show that the approach can be used to transform PbI₂ single crystals into high-quality, two-dimensional perovskite single crystals.

有机金属卤化物钙钛矿半导体可以潜在地用于创建具有高载流子迁移率的场效应晶体管（FET）。但是，这些晶体管的性能目前受到离子表面缺陷迁移的限制。在这里，我们显示了基于三个基于溶液的步骤的序列的表面清洁和钝化技术，可以减少卤化物基钙钛矿中离子表面缺陷的浓度，而不会干扰晶格。该方法包括使用极性/非极性溶剂的初始清洁步骤，去除表面有机卤化物空位的修复步骤以及第二清洁步骤。即使钙钛矿膜是在非优化条件下形成的，表面处理也能恢复干净，接近无磁滞的晶体管运行，与未经处理的薄膜相比，可以将室温FET的迁移率提高2到3个数量级。我们的甲基铵碘化铅（MAPbI₃）FET在300 K时分别具有3.0 cm ²  V ^-1  s ^-1和1.8 cm ²  V ^-1  s ^-1的高n型和p型迁移率，以及更高的值（9.2 cm ²  V ^-1  s）^-1；在80 K时为n型）。我们还证明该方法可用于将PbI ₂单晶转变为高质量的二维钙钛矿单晶。