Quasi-Two-Dimensional Perovskite Solar Cells with Efficiency Exceeding 22%

Abstract

Quasi-two-dimensional (quasi-2D) perovskites have attracted attention because they have better stability than the 3D counterpart. However, power conversion efficiency of perovskite solar cells (PSCs) based on quasi-2D perovskite still lags behind those of the devices with 3D perovskites. We report here on a quasi-2D PSC employing an alternating cation perovskite of multidimensional hybrid GA­(MA) n Pb n I3n+1 (n = 5) with a PCE over 22%, which is enabled by post-treatment with amphoteric imidazolium iodide (ImI). An optimal concentration of ImI reduces trap density and enhances charge mobility because of the improved phase purity and crystallinity, which eventually leads to a PCE of 22.26% with an open-circuit voltage of 1.19 V, a fill factor of 0.81, and a short-circuit current density of 22.99 mA/cm2. Moreover, a light-soaking stability test shows that ca. 94% of initial PCE is maintained after over 1200 h. The PCE achieved in this work is a record among the reported quasi-2D PSCs.

Spacer Organic Cation Engineering for Quasi‐2D Metal Halide Perovskites and the Optoelectronic Application

“…[ 81 ] Furthermore, when increasing n value to 5 (GA(MA) 5 Pb 5 I 16 ) and adopting posttreatment with amphoteric imidazolium iodide (ImI), a PCE over 22% can be reached. [ 82 ]…”

Stable and Bright CsPbX3 Nanocrystals in Metal–Organic Frameworks for White Light-Emitting Diodes

“…Over past decades, fluorescent materials have attracted much attention due to their excellent optical and electronic properties , as inorganic metal halide perovskite (CsPbX 3 , X = Cl, Br, and I) nanocrystals (NCs) have the advantages of tunable photoluminescence (PL), narrow emission spectra, and high PL quantum yields (PLQYs), showing important application potential. − Fluorescent CsPbX 3 NCs have been widely explored and studied in numerous fields such as in solar cells, light-emitting diodes (LEDs), and photodetectors. − With the development of science and technology, the application of perovskites has been extended to the fields of information anticounterfeiting, storage, and encryption. − Although the performance of CsPbX 3 perovskites is better than that of organic–inorganic hybrid perovskites, they are all poorly stable. Compared with inorganic hybrid perovskite, pure inorganic perovskite has the following three advantages: higher thermal stability, the thermal decomposition temperature of the former is 200 °C while that of the latter is 650 °C; higher device stability, all inorganic perovskites have good repeatability in multiple experimental tests, while the properties of organic–inorganic hybrid perovskites gradually decrease with the increase of test times; and prolonged lifetime, all inorganic perovskite devices can achieve long-term stable operations.…”

Quasi-2D halide perovskite crystals and their optoelectronic applications

“…The last decade has witnessed the explosive development of layered halide perovskites in high-performance optoelectronic devices (solar cells, 1–5 light-emitting diodes, 6–10 lasers, 11–15 photodetectors, 16–20 etc. ) due to their marvelous optoelectronic properties and high stability.…”