Stable Lead‐Free Tin Halide Perovskite with Operational Stability >1200 h by Suppressing Tin(II) Oxidation

Abstract

Sn-based perovskites are the most promising alternative materials for Pb-based perovskites to address the toxicity problem of lead. However, the development of Sn II -based perovskites has been hindered by their extreme instability. Here, we synthesized efficient and stable lead-free Cs 4 SnBr 6 perovskite by using SnF 2 as tin source instead of easily oxidized SnBr 2 . The SnF 2 configures a fluorine-rich environment, which can not only suppress the oxidation of Sn 2 + in the synthesis, but also construct chemically stable SnÀ F coordination to hinder the electron transfer from Sn 2 + to oxygen within the long-term operation process. The SnF 2 -derived Cs 4 SnBr 6 perovskite shows a high photoluminescence quantum yield of 62.8 %, and excellent stability against oxygen, moisture, and light radiation for 1200 h, representing one of the most stable lead-free perovskites. The results pave a new pathway to enhance the optical properties and stability of lead-free perovskite for high-performance light emitters.

Manipulating the sublattice distortion induced by Mn2+doping for boosting the emission characteristics of self-trapped excitons in Cs4SnBr6

“…These are the unique features of STEs caused by Jahn–Teller distortion of [SnBr 6 ] 4− octahedra in 0D perovskites. 14,28,29 In addition, the PL intensity of sample S-0 exhibits a linear relationship with the laser power ranging from 126 to 2816 nW. Therefore, green light with a broadband emitted from sample S-0 is attributed to radiative recombination of STEs ( i.e.…”

“…Very recently, Cs 4 SnBr 6 with long-term stability and a high PL QY of 62.8% was successfully fabricated by Zhang and coauthors through introduction of F − into Cs 4 SnBr 6 to suppress the oxidation of Sn 2+ . 14 From the practical application in white LEDs, the emission efficiency and thermal stability of Cs 4 SnBr 6 need to be further improved while its emission spectrum needs to be broadened.…”

Solution‐Processed Selective Area Homoepitaxial Growth of Suspended MAPbX3(X = Cl, Br) Perovskite Micro‐Arrays

“…[ 26–30 ] However, it is still very necessary to explore the efficiency‐enhanced routes for these devices to release the requirements on applied voltages and/or injection density and slow the degradation rates of perovskites under working conditions. [ 31–33 ]…”

Light Emission from Low‐Dimensional Pb‐Free Perovskite‐Related Metal Halide Nanocrystals

“…A higher stability of Sn 2+ ‐based NCs could be achieved following recent developments in their bulk counterpart, in which bulk Cs 4 SnBr 6 crystals with high oxygen, moisture and photostability were synthesized by utilizing SnF 2 as the Sn precursor instead of the typically used SnBr 2 . [ 147 ] In terms of device stability, the reported WLEDs have shown good operational stability. [ 31,53,55,88 ] However, due to the wide bandgap of the low‐D NCs, a UV excitation source is required for the phosphor‐type WLEDs, which leads to efficiency loss compared to if blue chips could be used.…”