摘要： Thanks to their broadly tunable band gap and strong absorption, colloidal lead chalcogenide quantum dots (QDs) are highly appealing as solution-processable active layers for third generation solar cells. However, the modest reproducibility of this kind of solar cell is a pertinent issue, which inhibits the exploitation of this material class in optoelectronics. This issue is not necessarily imputable to the active layer but may originate from different constituents of the device structure. This work is focused on the deposition of TiO2 electron transport layer. Atomic layer deposition (ALD) greatly improves the reproducibility of PbS QD solar cells compared to the previously optimized sol-gel (SG) approach. Power conversion efficiency (PCE) of the solar cells using ALD-TiO2 lies in the range between 5.5 and 7.2%, while solar cells with SG-TiO2 have PCE range from 0.5 to 6.9% with a large portion of short-circuited devices. Investigations of TiO2 layers by atomic force microscopy and scanning electron microscopy revealed that these films have very different surface morphology. While the TiO2 films prepared by sol-gel synthesis and deposited by spin coating are very smooth, TiO2 films made by ALD repeat the surface texture of the FTO substrate underneath.