In today's optoelectronic devices, particularly perovskite solar cells (PSCs), morphological engineering and microscopic architecture of metal oxide semiconducting materials are of great significance for enhanced charge collection, photonic structuring, and optical enhancement optimization. Herein, three-dimensional hollow TiO₂ sub-microspheres (3D-HTS) composed of anatase nanocrystals are synthesized using the hydrothermal method and used as a novel and efficient type of electron transport layer (ETL) for high-performance mesoscopic PSC. The TiO₂ sub–microsphere-based film features a 3D interconnected structure with tunable film thicknesses and pore sizes. The PSC based on such sub-microsphere films results in an outstanding power conversion efficiency (PCE) of 18.01% that is 28% greater than the TiO₂ nanoparticles (TNPs) ETL-based counterpart (PCE = 14.08%). The better efficiency of the sub–microsphere-made PSC device can be ascribed to the considerably improved charge collection, charge-transport, and light-harvesting capabilities. These valuable properties are because of the titania macropores that allow effective infiltration of the perovskite precursor for efficient light absorption, with reduced charge recombination and enhanced charge-transport through the sub-microspheres architecture. This work shows a practical and straightforward method for preparing 3D metal oxide–based electrodes for superior photovoltaic devices.

在当今的光电设备中，尤其是钙钛矿太阳能电池（PSC），金属氧化物半导体材料的形态工程和微观结构对于增强电荷收集，光子结构和光学增强优化具有重要意义。在此，使用水热法合成了由锐钛矿型纳米晶构成的三维空心TiO ₂亚微球（3D-HTS），并将其用作新型高效介电PSC的电子传输层（ETL）。TiO ₂亚微球基薄膜具有3D互连结构，其薄膜厚度和孔径可调。基于此类亚微球薄膜的PSC导致18.01％的出色功率转换效率（PCE），比TiO _2高28％基于ETL的纳米颗粒（TNP）（PCE = 14.08％）。亚微球制造的PSC装置的更高效率归因于电荷收集，电荷传输和光收集功能的显着改善。这些有价值的特性是由于二氧化钛大孔可以有效地吸收钙钛矿前体以实现有效的光吸收，同时减少了电荷复合并增强了通过亚微球结构的电荷传输。这项工作展示了一种实用而直接的方法，可以为高级光伏设备制备基于3D金属氧化物的电极。