The development of tin (Sn)‐based perovskite solar cells (PSCs) is hindered by their lower power conversion efficiency and poorer stability compared to the lead‐based ones, which arise from the easy oxidation of Sn2+ to Sn4+. Herein, phenylhydrazine hydrochloride (PHCl) is introduced into FASnI3 (FA = NH2CH NH2+) perovskite films to reduce the existing Sn4+ and prevent the further degradation of FASnI3, since PHCl has a reductive hydrazino group and a hydrophobic phenyl group. Consequently, the device achieves a record power conversion efficiency of 11.4% for lead‐free PSCs. Besides, the unencapsulated device displays almost no efficiency reduction in a glove box over 110 days and shows efficiency recovery after being exposed to air, due to a proposed self‐repairing trap state passivation process.
In analogy to their oxide counterparts,
two-dimensional (2D) hybrid
organic–inorganic perovskites have been classified, in many
cases, as either Dion–Jacobson (DJ) or Ruddlesden–Popper
(RP) structures. We quantified the offset of the inorganic layers
to allow the structures of hybrid organic inorganic perovskite to
be consistently related to these two structure types. We report the
structures of a family of 2D hybrid structures, (4-Y-C6H4CH2NH3)2PbI4 (where Y = F, Cl, Br, I), which consist of single ⟨100⟩-terminated
perovskite sheets separated by p-halobenzylammonium
cations. In contrast to the previous RP structure of (C6H5CH2NH3)2PbI4, where the inorganic layers are offset from each other, the Y =
F, Cl, and Br examples tend toward the DJ structure, in which successive
layers eclipse each other, despite the use of an organic monocation.
Close Y···I approaches suggest that
halogen bonding plays a role in these structures. Use of Y = I, for
which stronger halogen bonding is expected and is also suggested by
a more linear C–Y···I angle,
results in an RP-like structure. The stability of the (4-Y-C6H4CH2NH3)2PbI4 derivatives under ambient conditions is substantially higher for
Y = Br and I than for Y = H, F, and Cl.
Perovskite solar cells (PSCs) have achieved state‐of‐the‐art efficiency, approaching monocrystalline silicon solar cells due to the superior optoelectronic properties and intensive research efforts, fulfilling its forthcoming commercial use at affordable costs. Nevertheless, the toxicity of lead (Pb) is still one of the obstacles hindering future large‐scale production. Herein, the recent progress of emerging lead‐free tin (Sn)‐based PSCs is reviewed. First, the structural and photovoltaic‐related properties of Sn‐based perovskites are summarized. Following a brief introduction of film deposition methods, strategies recently adopted to obtain high performance are then discussed in detail. Finally, the current challenges and prospective opportunities are provided to help the further progression of Sn‐based PSCs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.