Mitigating ion migration in perovskite solar cells

Perovskite solar cells (PSCs) show great promise as a revolutionary photovoltaic (PV) technology. However, the instability issue caused by intrinsic ion migration is a major hurdle in the commercialization of this new PV technology. Recent progress in understanding the origins of intrinsic ion migration in metal halide perovskites and its impact on the degradation of each component layer in PSCs are briefly summarized. Strategies to mitigate ion migration are discussed, including engineering of perovskite composition, the incorporation of large organic cations, the introduction of ionic additives, the construction of robust charge-transfer layers and interfaces, and the development of corrosion-resistant electrodes. Intrinsic ion migration in the metal halide perovskite (MHP) absorber layer and its interfaces seriously limits the device stability of perovskite solar cells (PSCs). Despite considerable efforts to mitigate the ion migration issue, it remains a formidable challenge in the commercialization of PSCs. Here, we provide a short review of the device failure mechanisms induced by intrinsic ion migration and discuss the detrimental effects of ion migration on the different component layers of PSCs. We outline the corresponding strategies to mitigate ion migration in PSCs and provide an insight on materials engineering to attain long-term stabilized perovskite photovoltaics (PVs). Intrinsic ion migration in the metal halide perovskite (MHP) absorber layer and its interfaces seriously limits the device stability of perovskite solar cells (PSCs). Despite considerable efforts to mitigate the ion migration issue, it remains a formidable challenge in the commercialization of PSCs. Here, we provide a short review of the device failure mechanisms induced by intrinsic ion migration and discuss the detrimental effects of ion migration on the different component layers of PSCs. We outline the corresponding strategies to mitigate ion migration in PSCs and provide an insight on materials engineering to attain long-term stabilized perovskite photovoltaics (PVs). semiconductor layers with selective charge-transport properties for either electrons or holes. CTLs that selectively conduct electrons and holes are also called ETLs and HTLs, respectively. when the I-V characteristic of a solar cell is measured, the forward-scanning I-V curve (from negative voltage to positive voltage) differs from the reverse scanning (from positive voltage to negative voltage). a defect formed when an atom (or ion) leaves its lattice site, creating a vacancy, and becomes an interstitial. a 2D surface defect at the interface between two grains in a polycrystalline material. compounds comprising the periodic arrangement of the unit perovskite structure but with at least one reduced dimension, in contrast to 3D perovskites with unlimited extensions in all three dimensions. Low-D perovskites include 2D, 1D, and 0D perovskites. in mixed ionic–electronic semiconductors, both ions and electric charge carriers (electrons and holes) can conduct electricity. charge carriers in a semiconductor recombine releasing heat instead of light. the separation of grains or domains with different chemical gradients due to combinations of chemical and electromagnetic effects. Phase segregation introduces dislocations, GBs, stacking faults, or the interface between two phases. the conversion of photons directly into electricity using semiconducting materials. in ionic crystals, a Schottky defect forms when two oppositely charged ions leave their lattice sites, creating oppositely charged vacancies. current flows through low-resistance paths parallel to the main diode of a solar cell, causing power losses. a vacancy is a crystallographic defect where an atom is missing from one of the lattice sites in a crystal; an interstitial is a crystallographic defect where an atom intervenes in the space of the lattice sites in a crystal.