The long alkyl ligands on nanocrystal (NC) surfaces must be exchanged with short ligands to render NC films semiconducting for optoelectronic applications. It has become the consensus that through this process, it is unavoidable that detrimental cracks are induced due to the ligand volume loss. In this work, we demonstrate an advanced solid-state ligand exchange strategy to achieve crack-free PbS NC film in a single deposition step, through managing NC packing state and appropriate processing solvent selection. This strategy exhibits remarkable versatility for films with various thicknesses (up to 1 μm), substrates, and areas. The quality of the NC film is confirmed by solar cells as a representative application. The photovoltaic performance is on par with the reported state-of-the-art PbS NC solar cells. Our approach possesses the advantages of simplicity, “greener” processing, and lower materials costs, showing potential as a facile and reliable way to produce high-quality NC films for practical optoelectronic applications.

纳米晶体（NC）表面上的长烷基配体必须与短配体交换，以使NC薄膜在光电应用中成为半导体。已经达成共识，通过该过程不可避免地由于配体体积的损失而引起有害的裂纹。在这项工作中，我们演示了一种先进的固态配体交换策略，通过管理NC填充状态和适当的加工溶剂选择，可在单个沉积步骤中实现无裂纹的PbS NC膜。对于具有各种厚度（最大1μm）的薄膜，基材和面积，该策略均具有出色的多功能性。NC膜的质量已被太阳能电池确认为代表应用。光伏性能与已报道的最新PbS NC太阳能电池相当。