Perovskites have been firmly established as one of the most promising materials for third-generation solar cells. There remain several great and lingering challenges to be addressed regarding device efficiency and stability. The photovoltaic efficiency of perovskite solar cells (PSCs) depends drastically on the charge-carrier dynamics. This complex process includes charge-carrier generation, extraction, transport and collection, each of which needs to be modulated in a favorable manner to achieve high performance. Two-dimensional materials (TDMs) including graphene and its derivatives, transition metal dichalcogenides (e.g., MoS₂, WS₂), black phosphorus (BP), metal nanosheets and two-dimensional (2D) perovskite active layers have attracted much attention for application in perovskite solar cells due to their high carrier mobility and tunable work function properties which greatly impact the charge carrier dynamics of PSCs. To date, significant advances have been achieved in the field of TDM-based PSCs. In this review, the recent progress in the development and application of TDMs (i.e., graphene, graphdiyne, transition metal dichalcogenides, BP, and others) as electrodes, hole transporting layers, electron transporting layers and buffer layers in PSCs is detailed. 2D perovskites as active absorber materials in PSCs are also summarized. The effect of TDMs and 2D perovskites on the charge carrier dynamics of PSCs is discussed to provide a comprehensive understanding of their optoelectronic processes. The challenges facing the PSC devices are emphasized with corresponding solutions to these problems provided with the overall goal of improving the efficiency and stability of photovoltaic devices.

Recent progress in organic–inorganic halide perovskite solar cells (PSCs) has attracted great attention due to their impressive photovoltaic properties, and easy device manufacturing with facile layer deposition by solution processes, suggesting their great potential for large-scale applications. Remarkably, the power conversion efficiencies (PCEs) of PSCs have jumped from 3.8% of methyl ammonium lead halide, CH₃NH₃PbX₃ (X = Br, I), sensitized liquid solar cells in 2009, to more than 20% of all solid-state solar cells in 2015. Just over the past 6 years, numerous efforts have contributed to promote PSCs with more attractive properties, in preparation for future commercial applications, such as high PCE, high stability, high flexibility, large area, low cost, environmental friendliness, etc. In this review, we will concentrate on the recent advancements in the aspects of flexibility, stability and large scale of PSCs. We strive to present a comprehensive overview and show a deep understanding of the reported strategies for PSC devices with flexible, stable and large-scale properties.

Quantum dot-sensitized solar cells (QDSCs) are considered as promising candidates for cost-effective solar cells. This review comprehensively summarizes the recent rational strategies in material design for QDSCs with insights into photoanodes, QDs, electrolytes and counter electrodes.