Stabilities Related to Near-Infrared Quantum Dot-Based Solar Cells: The Role of Surface Engineering

As compared to the great effort made on improving the power conversion efficiency of quantum dot (QD) solar cells, investigations on relevant stability, regarded as another crucial factor for their widespread implementation, are still limited. In this perspective, we discuss the stability of QD solar cells from different aspects, all highly relying on the surface chemistry of QDs. Specifically, three types of stabilities, closely relevant to the realization of the actual application of QD solar cells, are presented: (i) air-processability, which allows QDs to be processed in air with high batch-to-batch reproducibility; (ii) long-term stability of QD solar cells, directly related to their performance degradation in the long run; and (iii) QD ink stability that is concerned with the storage lifetime of QDs in solution and is compatible with low-cost solution processing techniques. Both air processability and excellent QD ink stability are critical for achieving the desired low-cost, large-scale roll-to-toll manufacturing of solar cells.