Inorganic Halide Perovskite Solar Cells: Progress and Challenges

Abstract

All‐inorganic perovskite semiconductors have recently drawn increasing attention owing to their outstanding thermal stability. Although all‐inorganic perovskite solar cells (PSCs) have achieved significant progress in recent years, they still fall behind their prototype organic–inorganic counterparts owing to severe energy losses. Therefore, there is considerable interest in further improving the performance of all‐inorganic PSCs by synergic optimization of perovskite films and device interfaces. This review article provides an overview of recent progress in inorganic PSCs in terms of lead‐based and lead‐free composition. The physical properties of all‐inorganic perovskite semiconductors as well as the hole/electron transporting materials are discussed to unveil the important role of composition engineering and interface modification. Finally, a discussion of the prospects and challenges for all‐inorganic PSCs in the near future is presented.

Minimizing Voltage Losses in Perovskite Solar Cells

“…[ 61–63 ] For a more comprehensive discussion about minimizing the voltage loss of all‐inorganic PSCs, we refer to recently published Review articles that thoroughly summarized the feasible strategies to achieve stable and efficient all‐inorganic PSCs. [ 64,65 ] Unlike MACl and DMAI additives that easily volatilized during heat treatment, the introduction of MDACl 2 additive in the precursor solution could insert MDA 2+ divalent cation ( + H 3 NCH 2 NH 3 + , 262 pm) to partially substitute FA + cation ( + H 2 NCHNH 2 , 256 pm) in the FAPbI 3 lattices. [ 9 ] The presence of MDA 2+ in the perovskite lattice not only formed a stronger ionic interaction with I − due to increased hydrogen bonding and its divalent nature but also induced the formation of benign FA vacancies to relax the lattice strain.…”

2D Cs2PbI2Cl2 Nanosheets for Holistic Passivation of Inorganic CsPbI2Br Perovskite Solar Cells for Improved Efficiency and Stability

“…All‐inorganic CsPbX 3 (X = I, Br, and Cl or their mixture) perovskites have attracted great attention for their excellent optoelectronic properties and superior thermal stability. [ 1,2 ] Among them, CsPbI 2 Br possesses a high stability for preparing in air [ 3,4 ] and a suitable bandgap for solar‐spectrum absorption, [ 5,6 ] so it is considered to be an excellent candidate for fabricating efficient all‐inorganic perovskite solar cells (PSCs). However, the black‐phase CsPbI 2 Br (cubic α‐phase) is unstable under ambient conditions and tends to convert into the most stable non‐perovskite δ‐CsPbI 2 Br phase, which poses a major hurdle in the path toward commercial viability.…”

Perovskite Nanocrystals‐Based Heterostructures: Synthesis Strategies, Interfacial Effects, and Photocatalytic Applications

“…[ 58 ] As the crystal structure varies with the phases of perovskite, the Goldschmidt tolerance factor [ t ] and the octahedral factor [ μ ] have been widely adopted to judge the structural stability of perovskite. [ 59,60 ] …”

“…The range of [ t ]‐value for stable perovskite phases is usually between 0.8 and 1.0, and the ideal range of [ μ ] for a geometrically stable perovskite phase is roughly 0.44 < [ μ ] < 0.90. [ 59 ] Follow this principle, a cubic (α phase) perovskite could be obtained when the [ t ] value is between 0.9 and 1.0. [ 61–66 ] In general, the α phase perovskite is the ideal crystal structure for solar utilization due to perfect optoelectronic properties.…”