Recent Advancements in Crystalline Pb-Free Halide Double Perovskites

Abstract

Lead halide perovskites have gained more and more attention because of their ease of synthesis and excellent photoelectric properties including a large absorption coefficient, long carrier lifetime, long carrier diffusion length, and high carrier mobility. However, their toxicity, instability, and phase degradation in ambient environments impede their large-scale applications. To address these concerns, it is desirable to find stable alternative halide perovskites without toxicity and with comparable optoelectronic properties to lead-based perovskites. Over the years, a considerable number of lead-free halide perovskites have been added to this family of materials, including A2B’B’’X6, A2BX6, and A3B2X9 type perovskites. Among these, double perovskites with the general formula A2B’B’’X6 are deemed to be a potential alternative to lead halide perovskites as they possess good stability under ambient conditions and excellent optoelectronic properties. In this review, recent progress in exploring Pb-free halide double perovskites is highlighted. The synthesis, composition-tuning, physical properties, and applications of representative 3D, 2D, and nanocrystal A2B’B’’X6 double perovskites are introduced. In addition, perspectives about current challenges and solutions in this field are also provided.

Optoelectronic and photovoltaic properties of Cs 2 AgBiX 6 (X = Br, Cl, or I) halide double perovskite for solar cells: Insight from density functional theory

“…The chemical composition of double perovskite is diversified compared to the single perovskite family ABX 3 , where A atom constitutes a larger metal cation, such as Ca 2+ , and is surrounded by corner-sharing BX 6 octahedral sites, while B atom is a smaller metal cation, such as Ti 4+ , occupying the corner of the cube in the ideal cubic structure, and X atoms is an anion (frequently oxide) that bonds to both cations. 10 Thus, multiply the A into A 2 , B replaced by two cations B 0 and B 00 , and X doubled into to X 6 , leading to the formation of double perovskites with a general formula A 2 B 0 B 00 X 6 , where A cations are surrounded by a network of B 0 X 6 and B 00 X 6 octahedra. The first exploration of this unique family of perovskites materials was in 1960, whereas their synthesis using different combinations of A, B 0 , and B 00 cations proved the stability and the toxicity of their chemical components.…”

Mixed bismuth‐antimony‐based double perovskite nanocrystals for solar cell application

“…Their toxicity, instability, and phase degradation in ambient environments delay their large‐scale applications. Therefore, nontoxic halide double perovskites are being used in place of hybrid and inorganic lead‐based perovskite for solar cell applications 7 . Thus, A + B 2+ X − 3 ‐type perovskites are replaced by a less‐toxic materials (lead‐free and lead‐free double perovskite) A + 3 B 3+ 2 X − 9 , A + 2 B ′′ 4+ X − 6 and A + 2 B 3+ B ′ + X − 6 where A = Cs, Rb, and methylammonium, B 3+ = Bi, In, Sb, Au, and Fe, B ′ + = Ag, Au, Cu, B ′′ 4+ = Ti, Pd, and X = (Cl, Br, and I).…”

Toward eco‐friendly and stable halide perovskite‐inspired materials for light‐emitting devices applications by dimension classification: Recent advances and opportunities

“…In reality, some lead‐free eco‐friendly perovskites are termed as perovskite derivatives due to inconformity with the strict definition of perovskites that connected by the corner‐sharing BX 6 octahedra. So far, Sn(II)‐, Sn(IV)‐, Sb(Ш)‐, Bi(III)‐, Cu(I)‐, In(III)‐, Cu(II)‐, and Ag(I)‐based perovskites or perovskite derivatives have been successfully explored, and some of the lead‐free material systems show efficient emission comparable to that of Pb‐based perovskites 27–30 . Moreover, the synthesis process of such lead‐free perovskites is also relatively simple and highly repeatable 31–33 .…”

“…So far, Sn(II)-, Sn(IV)-, Sb(Ш)-, Bi(III)-, Cu(I)-, In(III)-, Cu(II)-, and Ag(I)-based perovskites or perovskite derivatives have been successfully explored, and some of the lead-free material systems show efficient emission comparable to that of Pb-based perovskites. [27][28][29][30] Moreover, the synthesis process of such lead-free perovskites is also relatively simple and highly repeatable. [31][32][33] It is worth mentioning that some leadfree perovskites emit typical broadband spectrum with high PLQY and superior stability, and they also present large Stokes shifts.…”