Perovskite photovoltaics have attracted remarkable attention recently due to their exceptional power conversion efficiencies (PCE). State-of-the-art perovskite absorbers typically require thermal annealing steps for high film quality. However, the annealing process adds cost and reduces yield for device fabrication and may also hinder application in tandem photovoltaics and flexible/ultra-low-cost optoelectronics. Herein, we report an additive-based room-temperature process for realizing high-quality methylammonium lead iodide films with micron-sized grains (>2 μm) and microsecond-range carrier lifetimes (τ₁ = 931.94 ± 89.43 ns; τ₂ = 320.41 ± 43.69 ns). Solar cells employing such films demonstrate 18.22% PCE with improved current–voltage hysteresis and stability without encapsulation. Further, we reveal that room-temperature-processed perovskite film grain size strongly depends on the precursor aggregate size in the film-deposition solution and that additive-based tuning of aggregate properties enables enlarging grains to the micron scale. These results offer a new pathway for more versatile, cost-effective perovskite processing.

中文翻译：

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具有微米级晶粒和微秒级载流子寿命的高性能室温处理钙钛矿吸收剂的添加工程

钙钛矿光伏产品最近因其出色的功率转换效率（PCE）而引起了人们的极大关注。最先进的钙钛矿吸收剂通常需要热退火步骤才能获得高质量的薄膜。然而，退火工艺增加了成本并降低了器件制造的成品率，并且还可能阻碍了在串联光伏和柔性/超低成本光电子学中的应用。在本文中，我们报道了用于与微米尺寸的颗粒实现高品质甲基铵碘化铅膜基于添加剂的室温处理（> 2微米）和微秒范围载流子寿命（τ ₁ = 931.94±89.43毫微秒; τ ₂= 320.41±43.69 ns）。采用这种薄膜的太阳能电池具有18.22％的PCE，具有改善的电流-电压滞后性和稳定性，而无需封装。此外，我们揭示了室温处理的钙钛矿薄膜的粒度在很大程度上取决于薄膜沉积溶液中前体的聚集体尺寸，并且基于添加剂的聚集体性质调节可将晶粒扩大至微米级。这些结果为更通用，更具成本效益的钙钛矿加工提供了一条新途径。