Inorganic CsPbI₃ Perovskite‐Based Solar Cells: A Choice for a Tandem Device

Abstract

Hygroscopicity risk and organic-inorganic hybrid perovskites easy decomposition in solar cells limit their usefulness. Apart from the hybrid organicinorganic perovskites, inorganic perovskite solar cells display a better stability toward moisture, light soaking, and thermal stressing. However, most inorganic perovskites are inappropriate for single junction or tandem solar cells due to their large bandgaps (>1.8 eV), which eventually results in light absorption loss. Fortunately, cubic CsPbI 3 perovskite (having 1.73 eV bandgap) could potentially serve as top cells in tandem devices with silicon solar cells. Poor phase stability of CsPbI 3 is considered a major obstacle to design CsPbI 3 perovskite solar cells. This review highlights the most recent studies on the progress in CsPbI 3 -based solar cell device field. Moreover, this review also summarizes certain strategies to improve phase stability, such as size reduction to nanocrystal or external cations/anions doping, with the aim to improve the devices design.

Synergy of Hydrophobic Surface Capping and Lattice Contraction for Stable and High‐Efficiency Inorganic CsPbI2Br Perovskite Solar Cells

“…Later, the dual halide CsPbI 2 Br was developed, and it has great advantages in terms of ambient phase stability and a more suitable band gap (1.91 eV) . Further study confirmed that the desired black phase CsPbI 2 Br is indeed tolerant to a range of degradation factors; however, it turns into the non‐perovskite orthorhombic phase upon exposure to a humid environment or water vapor . Hence, it is imperative to protect it against moisture ingress.…”

Soft Template‐Controlled Growth of High‐Quality CsPbI3 Films for Efficient and Stable Solar Cells

“…For this reason, all‐inorganic halide perovskites formed by substituting the organic cation with cesium (Cs) have become promising alternative candidates because of their inherent thermodynamic stability . Among these perovskites, black‐phase cesium lead iodide (CsPbI 3 ) has recently attracted great attention because of its excellent thermal stability and suitable optical bandgap (≈1.73 eV), which make it an ideal material for application in tandem cells combined with low‐bandgap photovoltaic materials . Nevertheless, the all‐inorganic CsPbI 3 perovskite without any volatile organic component faces serious challenges in terms of low‐phase stability.…”

Lattice Modulation of Alkali Metal Cations Doped Cs1−xRxPbBr3 Halides for Inorganic Perovskite Solar Cells

“…A solution to this impasse is to replace organic cations with inorganic cesium ion (Cs + ) to form cesium lead halide (CsPbX 3 , X = I, Br, Cl) light‐harvesters . Among these inorganic perovskites, CsPbI 3 has a more suitable bandgap of 1.73 eV, however, the notorious stability under low‐temperature and air‐atmosphere lead to the inferior performance . Till now, enormous efforts have proved that reducing iodide dosage of perovskite film can significantly improve the durability and photovoltaic performance.…”