The Fascinating Properties of Tin-Alloyed Halide Perovskites

Abstract

Tin-alloyed halide perovskites are progressively becoming more popular as slowly their optoelectronic properties start to rival those of the potentially risky pure lead analogues. However, to push this attractive semiconductor toward realistic applications, several major issues need to be solved. This Perspective will start with a description of the fundamental properties of tin-alloyed halide perovskites, continue discussing their weak points with special attention on the structural and electronic instabilities, and conclude examining the effects of the above-mentioned properties on devices. Finally we propose a plausible roadmap to further boost tin-alloyed halide perovskite devices to practical applications. We believe this roadmap should start from an understanding of this family of semiconductors from an atomistic viewpoint, proceeding to the control of thin-film fabrication, the structural properties, and finally the device optimization. We hope this Perspective can help to inject new enthusiasm and facilitate the progress in tin-alloyed halide perovskites, catalyzing their transition from the cradle of the laboratories to the reality of their fabrication.

Scalable, Template Driven Formation of Highly Crystalline Lead-Tin Halide Perovskite Films

“…Advanced Functional Materials published by Wiley-VCH GmbH future optimization of large area devices based on SnPb perovskites, as we forecasted recently. [33] The optimization will go through limiting the crack formation or curing them after ion exchange. Importantly, other compositions (FA/MA mixtures) giving better results in spin coated devices should also be used using the template method in future.…”

Advances and Challenges in Tin Halide Perovskite Nanocrystals

“…127,128 For THPs, the most studied alloyed structure is the SnPb alloyed perovskite films, showing not only enhanced device efficiency but also bandgap tunability and better structural stability. 39 Recently, SnPb alloyed halide perovskite NCs were also synthesized, which display superior stability compared with pure Sn-and Pb-based perovskite counterparts. 61,63 The first synthesis of alloyed CsSn 1−x Pb x I 3 NCs was reported in 2017, using TOP to dissolve SnI 2 and PbI 2 precursors.…”

“…37,38 Thus, Sn has been considered to be an ideal element to fully or partially replace Pb, leading to research on Pb−Sn alloyed perovskites with enhanced stability. 39 Although Sn is not fully nontoxic for human beings, a negligible bioavailability of Sn from Sn-based perovskites was confirmed because of the low water solubility of related Sn compounds. 32 Furthermore, tin iodide perovskites show a band gap of 1.3−1.4 eV, high carrier mobilities, and long carrier diffusion lengths, all of which favor the attainment of high-efficiency solar cells.…”

“…To address this issue, some elements including tin (Sn), germanium (Ge), bismuth (Bi), and antimony (Sb) have been developed for partly or thoroughly substituting Pb in the perovskite lattice. − In particular, Sn-based halide perovskites (THPs) have come under the spotlight by virtue of their low toxicity and outstanding electrical and optical properties. Compared to Pb, Sn has the same type of valence electron configuration (ns 2 sp 2 ) and close ionic radii (i.e., 1.19 and 1.18 Å for six-coordinated Pb 2+ and Sn 2+ ions, respectively). , Thus, Sn has been considered to be an ideal element to fully or partially replace Pb, leading to research on Pb–Sn alloyed perovskites with enhanced stability . Although Sn is not fully nontoxic for human beings, a negligible bioavailability of Sn from Sn-based perovskites was confirmed because of the low water solubility of related Sn compounds .…”

Metal Halide Perovskite and Perovskite−like Materials Through the Lens of Ultra−wideline 35/37Cl NMR Spectroscopy

“…17 Environmental concerns related to lead 18 and phase instability 19 remain as commercialization challenges for LHP−based photovoltaic technologies. Inevitably, group 14 cousin materials, viz., tin and germanium halide perovskites (GHPs) are gaining further attention in the search for lead−free alternatives, [20][21][22] while halide double perovskites (HDPs) [A2B'(III)B"(I)X6] consisting of corner−sharing alternate [B'(III)X6] 3− and [B"(I)X6] 5− octahedra with A−site cations residing in the cuboctahedral voids have shown improved ambient stability, excellent bandgap tunability and appealing light−emission properties. [23][24][25] Additionally, perovskite−inspired A2B(IV)X6 (B = Sn 4+ , Pd 4+ ) compounds, being air−stable and environment−friendly with tailorable optoelectronic capabilities, may provide an alternative direction.…”