Surface Passivation Toward Efficient and Stable Perovskite Solar Cells

Abstract

Although metal halide perovskites are increasingly popular for the next generation of efficient photovoltaic devices, the inevitable defects from the preparation process have become the notorious barrier to further improvement of performance, which increases non‐radiative recombination and lowers the power conversion efficiency of solar cells. Surface passivation strategies have been affirmed as one of the most practical approaches to suppress these defects. Therefore, it is necessary to have a detailed review on the surface passivation to reveal the improvements of the devices. Herein, the mechanism and recent advances of surface passivation have been systematically summarized with respect to various passivation approaches, including the Lewis acid–base, the low‐dimensional perovskite, inorganic molecules, and polymers. Finally, the review also offers the research trend and prospects of surface passivation.

Recent progress in perovskite solar cells: material science

“…Metal halide perovskite materials with excellent photoelectric properties have become the promising materials for the next generation of solar cells [406,407]. The high defect tolerance is the one reason for its excellent carrier transport and peculiar recombination properties [228].…”

“…Secondly, based on multi-quantum well structure, low-dimensional perovskite has unique exciton properties, and the "edge state" can dissociate excitons into long-lived free carriers directly, and then promote the carrier transport. Finally, wide-band gap 2D perovskite can also optimize the energy level structure, promote band alignment (Figure 29), passivate defects, reduce the density of defect state, and inhibit the ion migration [407]. Lowdimensional perovskites can be formed in situ on the top surface of perovskites, which greatly simplifies the process of forming heterojunctions.…”

Anchoring Vertical Dipole to Enable Efficient Charge Extraction for High‐Performance Perovskite Solar Cells

“…Surface passivation is a widely adopted strategy to modify the interfaces between the CTL and perovskite. [ 15 , 16 , 17 , 18 ] It has been reported that organic materials with electron‐rich carbonyl or amino functional groups can effectively passivate the under‐coordinated metal ions, contributing to improved device efficiency. [ 19 , 20 , 21 , 22 , 23 ] For example, Qiu et al.…”

Two-Dimensional Heterostructure of MoS2/BA2PbI4 2D Ruddlesden–Popper Perovskite with an S Scheme Alignment for Solar Cells: A First-Principles Study

“…12−15 Generally, the 2D perovskite could be described by the formula (A′) 2 (A) n−1 M n X 3n+1 , where A stands for a monovalent cation (e.g., Cs + , MA + , FA + ), M is a divalent metal cation (e.g., Pb 2+ , Sn 2+ ), X represents a halide anion (e.g., Cl − , Br − , I − ), and A′ is normally an large ammonium cation organic spacer such as BA + (butylamine: C 4 H 11 N) and PEA + (phenylethylammonium: C 8 H 12 N). 16 Since the M n X 3n+1 inorganic layers are intrinsically separated by the insulating intercalated A′ ions with finite electronic barriers, the 2D Ruddlesden−Popperphase perovskite acts as natural multiple quantum wells. 17 The thickness of the 2D layers is defined by the n value, which regulates the electronic and optical properties.…”

“…In contrast to MoS 2 , a 2D Ruddlesden–Popper (RP) metal halide perovskite is regarded as another emerging layered material with strikingly different structural and electronic properties that enable tunable optoelectronic properties and a high degree of structural flexibility. − Generally, the 2D perovskite could be described by the formula (A′) 2 (A) n −1 M n X 3 n +1 , where A stands for a monovalent cation (e.g., Cs + , MA + , FA + ), M is a divalent metal cation (e.g., Pb 2+ , Sn 2+ ), X represents a halide anion (e.g., Cl – , Br – , I – ), and A′ is normally an large ammonium cation organic spacer such as BA + (butylamine: C 4 H 11 N) and PEA + (phenylethylammonium: C 8 H 12 N) . Since the M n X 3 n +1 inorganic layers are intrinsically separated by the insulating intercalated A′ ions with finite electronic barriers, the 2D Ruddlesden–Popper-phase perovskite acts as natural multiple quantum wells .…”