Enhanced Charge Transport by Regulating the Electronic Structure in 2D Tin-Based Perovskite Solar Cells

Abstract

Tin-based perovskite has been widely studied due to its green, nontoxic, and excellent photoelectric physical properties. However, the high sensitivity of Sn2+ cations against moisture and oxygen was a huge challenge for preparing stable solar cells. In this study, 4-(aminomethyl) pyridine (4AP) cation is introduced to construct two-dimensional (2D) and Dion–Jacobson (DJ) perovskite 4APSnX4 (X = Cl, Br, I). First, through halogen component regulation, the charge transfer efficiency is improved. Then, it is found that increasing the temperature could build the charge transfer channel through an organic component and further improve the charge transfer efficiency. Finally, we prepared stable quasi-2D tin-based perovskite solar cells with the champion efficiency of 5.03%. We tracked the performance of unencapsulated devices over 200 h in an ambient environment (R.H. = 30%, T = 25 °C) and found no appreciable decay in efficiency. This study provides a new strategy for solving the transmission and stability problem of 2D tin perovskite.

Many-Body Effects on the Electronic and Optical Properties of Lead-Free KNbO3–xQx (x = 0, 1, 2; Q = S, Se) Oxychalcogenide Perovskites

“…Since bound excitons have longer lifetimes and are less prone to recombination, , OCGP compounds are ideal for applications, such as photovoltaics and light-emitting devices. Besides, the stability of bound excitons suggests that the compounds have the potential for efficient charge transport and improved device performance. , …”

The rise of quasi-2D Dion–Jacobson perovskites for photovoltaics

“…Li and co-workers introduced a 4AP 2+ cation to construct the 2D DJ perovskite 4APSnX 4 . 80 They found that high temperature was able to provide a charge transfer channel and further enhance the charge transfer efficiency.…”

“…78 Furthermore, replacement of Pb with Sn allows a suitable bandgap, a high carrier mobility, and a low E b for quasi-2D DJ perovskites. Research studies on Sn or Sn/Pb based DJ phase perovskites with 3AMP, 79 4-(aminomethyl)pyridinium (4AP 2+ ), 80 and BDA 81 organic spacers have also been reported recently.…”

Effects of ambient exposure on photoluminescence of Dion–Jacobson tin-based halide perovskites

“…26 DJ perovskites incorporate diammonium cations which are bound by hydrogen bonds to the layers of inorganic metal halide octahedra and exhibit no offset of inorganic layers. 26 Different 2D (single layers of inorganic tin halide octahedra separated by spacer cations) and quasi-2D (multiple layers of inorganic tin halide octahedra separated by spacer cations) tin halide perovskites have been reported to date, [1][2][3][5][6][7][8]17,22,[27][28][29][30][31][32][33][34] including both RP 1,2,[6][7][8]17,22,30,34 and DJ 3,5,[27][28][29][30][31][32][33] perovskite materials. In general, these materials exhibit improved stability compared to 3D tin-based perovskites.…”