Ruddlesden-Popper quasi-2D perovskites represent robust candidates for optoelectronic applications, achieving a delicate balance between outstanding photoresponse and stability. However, mitigating the internal defects in polycrystalline films remains challenging, and their optoelectronic performances still lag behind that of their 3D counterparts. This work highlights the profound impact of defect passivation at the buried interface and grain boundaries through a dual-cation-release strategy. Cations released from the pre-deposited inorganic iodide buffer layer effectively repair deep-level defects by inducing low-dimensional phase reconstruction and interacting with undercoordinated ions. The resulting quasi-2D perovskite polycrystalline films feature large grain size (>2 µm) and minimum surface roughness, along with alleviated out-of-plane residual tensile strain, which is beneficial for inhibiting the initiation and propagation of cracks. The fabricated photodetector demonstrates drastically improved self-powered photoresponse capability, with maximum responsivity up to 0.41 A W⁻¹ at 430 nm and an ultrafast response speed of 161 ns / 1.91 µs. Moreover, this strategy is compatible with the photolithography-assisted hydrophobic-hydrophilic patterning process for fabricating pixelated photodetector arrays, which enables high-sensitivity imaging. This study presents a feasible defect passivation approach in quasi-2D perovskites, thereby providing insights into the fabrication of high-performance optoelectronic devices.

中文翻译：

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准 2D 钙钛矿中的有效双阳离子释放，用于超快紫外光成像


Ruddlesden-Popper 准 2D 钙钛矿代表了光电应用的可靠候选者，在出色的光响应和稳定性之间实现了微妙的平衡。然而，减轻多晶薄膜的内部缺陷仍然具有挑战性，并且它们的光电性能仍然落后于 3D 同类产品。这项工作通过双阳离子释放策略强调了埋藏界面和晶界缺陷钝化的深远影响。从预沉积的无机碘化物缓冲层释放的阳离子通过诱导低维相重构和与配位不足的离子相互作用来有效修复深层缺陷。所得的准 2D 钙钛矿多晶薄膜具有大晶粒尺寸 （>2 μm） 和最小的表面粗糙度，以及减轻的平面外残余拉伸应变，这有利于抑制裂纹的萌生和扩展。制造的光电探测器表现出显著提高的自供电光响应能力，在 430 nm 处的最大响应度高达 0.41 A ^W-1，超快响应速度为 161 ns/1.91 μs。此外，该策略与用于制造像素化光电探测器阵列的光刻辅助疏水亲水图案化工艺兼容，从而实现高灵敏度成像。本研究提出了一种在准 2D 钙钛矿中可行的缺陷钝化方法，从而为高性能光电器件的制造提供了见解。