The adoption of new thin-film materials in high-end technologies, such as monolithic tandem solar cells and integrated circuits, demands fabrication processes that allow a high level of control over film properties such as thickness, conformality, composition, and crystal structure. Achieving this with traditional optoelectronic materials, such as silicon, indium phosphide, gallium arsenide, silicon nitride, and several metal oxides, has opened the way for applications such as high-efficiency photovoltaics, light emitting devices, and integrated photonics. More recently, halide perovskites have demonstrated huge potential in optoelectronic applications, showing exceptional photovoltaic properties, light emission, and lasing performance. Common growth techniques for these halide perovskites have been solution-based methods. Optimized solution-based processes yield high quality thin films well-suited for applications, such as single-junction solar cells, but remain incompatible with integration into complex devices such as monolithic tandem photovoltaics and photonic circuits. Therefore, new fabrication methods allowing atomic, structural, and compositional precision with the conformal growth of hybrid and multi-compound halide perovskite thin films are of utmost importance for material exploration and for their application in complex devices. This Perspective reviews the progress on synthesis methods of halide perovskite thin films, discusses pressing challenges, and proposes strategies for growth control, versatile film deposition, monolithic device integration, epitaxial growth, and high-throughput synthesis to discover novel and non-toxic stable metal halide compositions.

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卤化物钙钛矿薄膜生长的紧迫挑战

在单片串联太阳能电池和集成电路等高端技术中采用新型薄膜材料，要求制造工艺能够对薄膜特性（如厚度、共形性、成分和晶体结构）进行高度控制。使用硅、磷化铟、砷化镓、氮化硅和几种金属氧化物等传统光电材料实现这一目标，为高效光伏、发光器件和集成光子学等应用开辟了道路。最近，卤化物钙钛矿在光电应用中显示出巨大的潜力，显示出卓越的光伏特性、发光和激光性能。这些卤化物钙钛矿的常见生长技术是基于溶液的方法。优化的基于溶液的工艺产生非常适合应用的高质量薄膜，例如单结太阳能电池，但仍然不兼容集成到复杂设备中，例如单片串联光伏和光子电路。因此，通过混合和多化合物卤化物钙钛矿薄膜的共形生长来实现原子、结构和成分精度的新制造方法对于材料探索及其在复杂设备中的应用至关重要。该观点回顾了卤化物钙钛矿薄膜合成方法的进展，讨论了紧迫的挑战，并提出了生长控制、多功能薄膜沉积、单片器件集成、外延生长、