Fig 1

Progress in efficiency of tin-based perovskite solar cells."

Fig 2

(a) Atomic structure diagram of MASn(I, Br)3; (b) unit cell of MASn(I, Br)3; (c) conductivity and Seebeck coefficient for a MASnI3 sample. (d) Absorption spectra of MASn(I, Br)3. (e) XRD patterns of MASn(I, Br)3. (a, b) Reproduced with permission 36, Copyright 2013, American Chemical Society. (c-e) Reproduced with permission 29, Copyright 2014, Nature Publishing Group. "

Fig 3

(a) Atomic structure diagram of FASn(I, Br)3; (b) unit cell of FASn(I, Br)3; (c) electronic absorption spectra of various Sn-based perovskites; (d) TGA and DSC data for MASnI3 and FASnI3. (e) Current of the MASnI3 and FASnI3 conductor structures. (a-c) Reproduced with permission 35, Copyright 2013, American Chemical Society. (d) Reproduced with permission 39, Copyright 2016, Wiley-VCH. (e) Reproduced with permission 41, Copyright 2016, Wiley-VCH. "

Fig 4

(a) A phase transition diagram for CsSnI3; (b) SEM of CsSnI3 PSCs; (c) scheme of the CsSnI3 perovskite solar cells; (d) J-V curve of CsSnI3 solar cell. (a) Reproduced with permission 44, Copyright 2019, Wiley-VCH. (b) Reproduced with permission 45, Copyright 2019, Progress in Chemistry. (c, d) Reproduced with permission 69. Copyright 2016, Wiley-VCH. "

Fig 5

SEM images of the MASnI3 perovskite films from different solvents 57. (a) DMF, (b) NMP, (c) DMSO, (d) DMSO. Reproduced with permission, Copyright 2015, American Chemical Society. "

Fig 6

(a) The processing of the solvent-engineering method. (b-e) SEM images of FASnI3 films 30. (b) without anti-solvent, (c) with chlorobenzene, (d) with toluene, (e) with diethyl ether. (b-e) Reproduced with permission, Copyright 2016, Wiley-VCH. "

Fig 7

(a) Schematic of VASP method; SEM images of (b) one-step MASnI3, (c) VASP MASnI3, (d) LT-VASP-MASnI3; SEM images of (e) the as-deposited SnI2 and (f) annealed SnI2; (g) J-V curves of devices prepared by different methods 56. Reproduced with permission, Copyright 2016, American Chemical Society. "

Fig 8

SEM images of FASnI3 films without pyrazine (a), with pyrazine (b); (c) SEM images of FASnI3 films with SnF2; (d) SEM images of FASnI3 films with SnF2 and TMA. (a, b) Reproduced with permission 61, Copyright 2016, American Chemical Society. (c, d) Reproduced with permission 63. Copyright 2017, Wiley-VCH. "

Fig 9

(a) Molecular formula of FA and PPA; (b) schematic representations ofcrystal structure of PPAxFA1-xSnI3; (c-h) SEM images and (i) statistics of grain size distribution of PPAxFA1-xSnI3 films with different PPAI contents; (j) photographs of FASnI3 films with and without PPAI during annealing at 100 ℃ 34. Reproduced with permission, Copyright 2019, Elsevier Inc. "

Fig 10

(a) SEM images of MASnI3 device with regular mesoporous structure. (b) The solar cell performance parameters extracted from J-V curves. (c) FASnI3 solar cells with regular planar structure. (d) J-V curves of the regular planar solar cells based on FASnI3 absorbers. (a, b) Reproduced with permission 64. Copyright 2014, The Royal Society of Chemistry. (c, d) Reproduced with permission 63. Copyright 2017, Wiley-VCH. "

Fig 11

(a) Scheme of the CsSnI3 perovskite solar cells; (b) J-V curve of CsSnI3 solar cell; (c) schematic of energy level diagram of the FASnI3 perovskite solar cells with planar inverted structure; (d) J-V curves of a planar inverted FASnI3 perovskite solar cell."

Fig 12

Energy diagram of Pb- and Sn-based perovskites, ETLs, and HTLs."