Stabilizing and scaling up carbon-based perovskite solar cells

Organometal trihalide perovskite solar cells (PSCs) have sparked a frantic excitement in the scientific community because they can achieve high power conversion efficiencies (PCEs) even when fabricated by low-cost solution-processing technologies. However, the poor stability of PSCs has seriously hindered their commercialization. Among various kinds of PSCs, carbon-based PSCs without hole transport materials (C-PSCs) seem to be the most promising for addressing the stability issue because carbon materials are stable, inert to ion migration, and inherently water-resistant. Concurrent with the steady rise in PCE of C-PSCs, great progresses have also been attained on the device stability and scaling-up fabrication of C-PSCs, which have well signified the possible commercialization of PSCs in the near future. In this review, we will summarize these progresses with a view of exposing the promising prospect. We start by collating recent stability testing results of C-PSCs with reference to those of HTM-PSCs. Then, we update the research status on large-scale C-PSCs and their associated scalable fabrication technologies. Finally, we identify main issues to be addressed alongside future research directions.