Shedding Light on the Moisture Stability of Halide Perovskite Thin Films

Abstract

To date, remarkable progress has been achieved in the power conversion efficiency of perovskite solar cells (PSCs). Nevertheless, the instability and degradation of PSCs under external stimuli still shadow the prospectus of their commercialization. As a notorious culprit deteriorating the stability of PSCs, moisture‐induced degradation is thereby an important aspect. Herein, a comprehensive review of moisture effects on the halide perovskite film, in particular the moisture‐induced degradation mechanism and methods toward enhancing the stability, is discussed. In detail, the benefits for perovskite films having a certain amount of water incorporation are elucidated, and the underlying moisture‐induced structural degradation and decomposition process of perovskites are summarized. Light is also shed on the methods to enhance the moisture stability of perovskites, particularly a 3D/2D heterostructure. Thereby, this review will enlighten the readers of understanding moisture‐induced degradation and the development of stable perovskites.

Morphological Insights into the Degradation of Perovskite Solar Cells under Light and Humidity

“…Also, our results illustrate that there is no perovskite decomposition after aging. Therefore, the ex situ GIWAXS experiments manifest that water molecules are not interacting with perovskite absorbers during this aging period; however, longer exposure to light and high humidity would lead to the hydration and even decomposition of the perovskites . In order to track the evolution of the crystal lattice, we fit the (100) peak with Gaussian functions as illustrated in Figure e,f.…”

Green Solvent Polishing Enables Highly Efficient Quasi-2D Perovskite Solar Cells

“…The OIHP solar cells have reached an impressive power conversion efficiency (PCE) over 25% . However, the bottleneck for the perovskite solar cells (PSCs) is the vulnerability to moisture, heat, and oxygen. − In recent years, quasi-2D perovskites, acting as alternatives to the traditional 3D counterparts, have shown great potential in resisting moisture and oxygen. − Besides the superior stability, the quasi-2D perovskites present flexible choices of the bulky cations and less restriction of the tolerance factor, enabling diverse structures and tunable physical properties. , Basically, quasi-2D perovskites are formed by inserting bulk organic cations into the Pb–I frameworks. For the most common Ruddlesden–Popper quasi-2D perovskites, the generic chemical formula is A’ 2 A n– 1 M n X 3 n +1 where the A’ is the bulky organic cation (butylamine ion (BA + ), phenethylammonium ion (PEA + ), etc.)…”

2D/3D Perovskite Photodetectors with High Response Frequency and Improved Stability Based on Thiophene-2-ethylamine and Dual Additives

“…Organic–inorganic halide perovskite materials are one of the most promising flexible and low-cost photoharvesting technologies. − Recently, 3D MAPbI 3 -based photodetectors have drawn great the attention of researchers due to their broad absorption, high responsivity, and high response frequency, whose performance might exceed that of silicon devices. , However, several factors such as moisture, heat, and illumination can induce ion migration, phase separation, and degradation of the MAPbI 3 perovskite films. − The poor stability of the 3D MAPbI 3 perovskite greatly limits its commercial application and further development in photodetection. To improve the stability of perovskite materials, two-dimensional (2D) Ruddlesden–Popper (RP) perovskites are widely used in the field of optoelectronic devices. − The general formula of the RP perovskites can be written as (RNH 3 ) 2 (A) n −1 M n X 3 n +1 where RNH 3 is a large organic spacer, A is CH 3 NH 3 + or HC­(NH 2 ) 2 + , M = Pb 2+ or Sn 2+ , and X is a halide ion.…”