Perovskite Colloidal Nanocrystal Solar Cells: Current Advances, Challenges and Future Perspectives.

The power conversion efficiencies (PCEs) of polycrystalline perovskite (PVK) solar cells (SCs) (PC-PeSCs) have been rapidly increased. However, PC-PeSCs are intrinsically unstable without encapsulation, and their efficiency drops during large-scale production; these problems hinder the commercial viability of PeSCs. Stability can be increased by using colloidal PVK nanocrystals (c-PeNCs), which have high surface strains, low defect density, and exceptional crystal quality. Use of c-PeNCs separates the crystallization process from film formation process, which is preponderant in large-scale fabrication. Consequently, use of c-PeNCs has substantial potential to overcome challenges encountered when fabricating PC-PeSCs. Research on colloidal nanocrystal-based PVK SCs (NC-PeSCs) has increased their PCEs to the level greater than those of other quantum-dot SCs, but has not reached the PCEs of PC-PeSCs; this inferiority significantly impedes widespread application of NC-PeSCs. This review at first introduces the distinctive properties of c-PeNCs, then the strategies that have been used to achieve high-efficiency NC-PeSCs. Then it discusses in detail the persisting challenges in this domain. Specifically, the major challenge and solutions for NC-PeSCs related to low short-circuit current density Jsc are covered. Lastly, the article presents a perspective on future research directions and potential applications in the realm of NC-PeSCs. This article is protected by copyright. All rights reserved.