Thiocyanate Complexes of Lead and Thallium in Solution

Pseudohalide‐Induced Moisture Tolerance in Perovskite CH3NH3Pb(SCN)2I Thin Films

“…Thef ormation constant K 4 (cumulative formation constant b n = K 1 K 2 …K n )h as been calculated to be only 3.5 for PbI 4 2À , [18] which is in the range of the weak interactions between I À and Pb 2+ .I nt he case of CH 3 NH 3 Pb(SCN) 2 I, the interaction between Pb 2+ and SCN À is much stronger,and the formation constant K 4 is up to 7f or Pb(SCN) 4 2À . [19] Comparing the spherical shape of I À ions with the linear shape of SCN À ions as indicated by their Lewis structures,the lone pairs of electrons from the Sand Natoms in SCN À can interact strongly with the Pb ion, which in turn stabilizes the frame structure of CH 3 NH 3 Pb(SCN) 2 I. We show that ad irect improvement of moisture tolerance has been observed for CH 3 NH 3 Pb(SCN) 2 Iinaccelerated stability tests compared with the traditional CH 3 NH 3 PbI 3 perovskite material.…”

Pseudohalide‐Induced Moisture Tolerance in Perovskite CH3NH3Pb(SCN)2I Thin Films

“…The formation constant K 4 (cumulative formation constant β n = K 1 × K 2 ×…︁ K n ) has been calculated to be only 3.5 for PbI 4 2− ,18 which is in the range of the weak interactions between I − and Pb 2+ . In the case of CH 3 NH 3 Pb(SCN) 2 I, the interaction between Pb 2+ and SCN − is much stronger, and the formation constant K 4 is up to 7 for Pb(SCN) 4 2− 19. Comparing the spherical shape of I − ions with the linear shape of SCN − ions as indicated by their Lewis structures, the lone pairs of electrons from the S and N atoms in SCN − can interact strongly with the Pb ion, which in turn stabilizes the frame structure of CH 3 NH 3 Pb(SCN) 2 I.…”

Low‐Pressure Vapor‐Assisted Solution Process for Thiocyanate‐Based Pseudohalide Perovskite Solar Cells

“…Another approach to achieve better stability is the layereds tructure with 2D perovskite, which delivers higher moisture resistance than 3D MAPbI 3 structure. [16] Inspired by these results, we employed Pb(SCN) 2 as precursor for the synthesis of hybrid perovskite using low-pressure vapor assisted solution process (LP-VASP) methodf or the first time. Lead salt precursors,s uch as lead acetate or lead nitrate,a re great candidate precursors for forming perovskites with high PCE of 17 %a nd 12 %, respectively.…”

“…[15] The impact of thiocyanate on structure stabilityr esults from the favorable thermodynamic properties of large formation constant between Pb and SCN. [16] Inspired by these results, we employed Pb(SCN) 2 as precursor for the synthesis of hybrid perovskite using low-pressure vapor assisted solution process (LP-VASP) methodf or the first time. Photovoltaicd evices based on SCN-containing perovskite have reached 15 % PCE and demonstrate excellent ambient stabilityc ompared In this report, we fabricated thiocyanate-based perovskite solar cells with low-pressure vapor-assisted solution process (LP-VASP) method.…”