FA/MA Cation Exchange for Efficient and Reproducible Tin-Based Perovskite Solar Cells

Abstract

Nontoxic tin-based perovskite solar cells (Sn-PSCs) as a promising alternative to toxic Pb-PSCs have drawn great attention in recent years for their environmental friendliness and unique optoelectronic properties. However, both the efficiency and long-term stability of Sn-PSCs are considerably inferior to those of Pb-based ones. One of the main reasons is the difficulty in obtaining high-quality Sn-perovskite films due to the rapid crystallization of Sn-perovskites, which also results in poor device reproducibility. Here, we report a novel cation exchange strategy to prepare high-quality formamidinium tin triiodide (FASnI3) perovskite films with a better controlled crystallization process and improved reproducibility, which allows easy access to smooth and pinhole-free perovskite films with oriented crystal growth, enlarged grain size, and reduced trap-state density. The corresponding Sn-PSCs show excellent photovoltaic performance with a champion efficiency of 9.11%, comparable to the best results reported for FASnI3-PSCs, and the devices also demonstrate outstanding long-term stability without encapsulation. Our results offer a practical strategy for fabricating Sn-PSCs with superb performance and stability.

SnOx as Bottom Hole Extraction Layer and Top In Situ Protection Layer Yields over 14% Efficiency in Sn-Based Perovskite Solar Cells

“…However, the sensitivity of humidity and acidity of PEDOT:PSS limits the improvement of PSCs stability and performance. − Therefore, searching for an inorganic alternative is an important part for industrial application due to its intrinsic stability and low-cost. At present, the best PCEs of 9.03% and 7.34% were reported for inorganic NiO x and CuSCN in S-PSCs, which are still lower than for the PEDOT:PSS counterparts. , Besides, the energy level mismatch also limits the improvement of device performance. − …”

“…At present, the best PCEs of 9.03% and 7.34% were reported for inorganic NiO x and CuSCN in S-PSCs, which are still lower than for the PEDOT:PSS counterparts. 10,11 Besides, the energy level mismatch also limits the improvement of device performance. 12−17 SnO 2 is a famous ETL in PSCs due to its simple preparation process and high device performance.…”

Exploring the Effect of Kesterites and Zinc‐Based Charge Transport Materials on the Device Performance and Optoelectronic Properties of FAPbI3Perovskite Solar Cells

“…[ 2,3 ] One of the most rigorously researched perovskite materials, methyl ammonium lead triiodide (MAPbI 3 ), has successfully achieved power conversion efficiency (PCE) of more than 25%, overtaking the majority of its competitors in performance. [ 4–7 ]…”

“…[2,3] One of the most rigorously researched perovskite materials, methyl ammonium lead triiodide (MAPbI 3 ), has successfully achieved power conversion efficiency (PCE) of more than 25%, overtaking the majority of its competitors in performance. [4][5][6][7] The perovskite materials have ABX 3 crystal structure. The "A" in the structure represents the "organic/inorganic" cation, the "B" represents the "metal" cations, and the "X" represents the "halide" anions.…”

Surface and Interfacial Passivations for FASnI3 Solar Cells with Co-Cations

“…In addition to these two additives, other cationic additives have been widely considered for TPSCs. For example, methylammonium (MA), ethylammonium (EA), 2-hydroxyethylammonium (HEA), dimethylammonium (DMA), aziridinium (AZ), imidazolium (IM), guanidinium (GA), and so on have been applied as A-site cocations to cocrystallize with FA to form cocationic tin perovskites for enhanced performance and stability for TPSCs. These cocationic approaches were performed according to a one-step fabrication procedure for which all tin perovskite precursors were added together in a solution to deposit on the hole-transport layer poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS) in one step.…”