Pb-free halide perovskites for solar cells, light-emitting diodes, and photocatalysts

Abstract

Metal halide perovskites have recently emerged as one of the most promising classes of semiconductors for various applications, especially in the field of optoelectronics. Lead-based halide perovskite materials, virtually unexploited for decades, have become prominent candidates due to their unique and intrinsic physicochemical and optical properties. Current challenges faced by the scientific community to capitalize on the properties of Pb-based perovskites are mainly associated with environmental concerns due to the toxicity of Pb and their poor stability. Under this context, over recent years, a number of new Pb-free halide perovskite (and perovskite-like) semiconductor classes have been introduced. This Perspective reviews recent developments in Pb-free halide perovskites, which specifically target their application in solar cells, light-emitting devices, and photocatalysts. Each type of Pb-free material is paired with a specific optoelectronic application, and the latest record performances are reported. Although these materials do not yet exhibit as attractive intrinsic optoelectronic properties as the Pb-based halide perovskites, their potential as alternatives for well-suited applications is discussed.

Silver–Bismuth Halide Double Salts for Lead‐Free Photovoltaics: Insights from Symmetry‐Based Modeling

“…These PCE values are among the highest achieved for lead-free perovskites and perovskite-like materials, excluding the less stable Sn-based materials. [24] Materials that are more on the Bi-rich side like AgBi 2 I 7 tend to exhibit poorer performances in optoelectronic devices. [17,19] In a further attempt to improve device performance, the partial and total replacement of both Ag and Bi were investigated.…”

Anharmonic electron-phonon coupling in polymorphous perovskites

“…Oxide perovskites are fascinating materials with extensive applications owing to their intrinsic ferroelectric, antiferroelectric, and piezoelectric properties 1 . Halide perovskites are of high interest due to their impressive efficiencies in solar cells 2,3 , and attractive applications in optoelectronics, electrocatalysis, and thermoelectrics [4][5][6] . Our understanding of perovskites' key properties is connected to deviations of the vibrational dynamics and electron-phonon coupling from the standard picture observed in conventional semiconductors 7,8 .…”

Lead-Free Halide Perovskites for Photocatalysis via High-Throughput Exploration

“…Pb-free HP NCs are promising alternatives due to their distinctive physicochemical and optical attributes. The research advancements of Pb-free HPs are due to their tunable optical band gap ranging from 3.1 (400 nm) to 1.4 eV (885 nm), − large absorption coefficient with a reduced recombination of photoinduced charge carriers, defect tolerance, long diffusion length of the charge carrier, and nontoxicity compared to their Pb-based counterparts. Moreover, these materials demonstrate impressive electrical properties, such as efficient charge transport.…”

“…HPs exhibit expansive compositional spaces and can be crafted with extensive structural variability and dimensionality ranging from 0D to 3D, including quasi-2D HPs. Figure presents a succinct collection of prospective Pb-free HPs for photocatalysis, spanning from 3D to 0D structures, predicated on their light absorption attributes. ,, 3D HPs emerge as prominently investigated materials owing to their light absorption coefficients, proficient solution processing capabilities at low temperatures, and extensive exciton diffusion lengths. Nevertheless, the challenges associated with stability and the recombination of charge carriers necessitate resolution before their effective deployment in practical photocatalytic applications.…”

“…The tolerance factor ( t ) in 3D HPs is between 0.8 and 1, but when t < 0.8 or t > 1 it adapts to a low-dimensional structure, like 2D HPs. The general formula for 2D HPs is (RNH 3 ) 2 A n –1 B n X 3 n +1 , where n is the number of stacked corners shared octahedral layers [ n = 1, 2D; n = ∞, 3D; and 1 < n < ∞, quasi-2D], ,, as shown in Figure . In the class of 2D HPs, a key aspect of their classification revolves around crystallographic orientation, specifically along the (100), (110), and (111) directions.…”