Heterogeneous 2D/3D Tin‐Halides Perovskite Solar Cells with Certified Conversion Efficiency Breaking 14%

Abstract

As the most promising lead‐free one, tin‐halides based perovskite solar cells still suffer from the severe bulk‐defect due to the easy oxidation of tin from divalent to tetravalent. Here, a general and effective strategy is delivered to modulate the microstructure of 2D/3D heterogeneous tin‐perovskite absorber films by substituting FAI with FPEABr in FASnI3. The introduction of 2D phase can induce highly oriented growth of 3D FASnI3 and it is revealed in the optimal 2D/3D film that 2D phase embraces 3D grains and locates at the surfaces and grain boundaries. The FPEA+ based 2D tin‐perovskite capping layer can offer a reducing atmosphere for vulnerable 3D FASnI3 grains. The unique microstructure effectively suppresses the well‐known oxidation from Sn2+ to Sn4+, as well as decreasing defect density, which leads to a remarkable enhanced device performance from 9.38% to 14.81% in conversion efficiency. The certified conversion efficiency of 14.03% announces a new record and moves a remarkable step from the last one (12.4%). Besides of this breakthrough, this work definitely paves a new way to fabricate high‐quality tin‐perovskite absorber film by constructing effective 2D/3D microstructures.

Assessment of Lead‐Free Tin Halide Perovskite Solar Cells Using J–V Hysteresis

“…Yu et al recently achieved a PCE of 14.81% with a certified conversion efficiency of 14.03% for FASnI 3 -based inverted PSCs by adding 4-fluorophenethylammonium bromide (FPEABr) into the perovskite precursor solution to fabricate a 2D/3D mixed tin perovskite films. [120] They added different ratios of FPEABr in the precursor solution to effectively modulate the microstructure of 2D/3D heterogeneous perovskite film. It is observed that devices with 10% FPEABr showed the highest PCE.…”

Fullerene Derivative with Flexible Alkyl Chain for Efficient Tin-Based Perovskite Solar Cells

“…Tin-based halide perovskite materials have attracted much attention due to their low toxicity, suitable band gap, and their rapid improvement of the performance of photovoltaic devices [ 1 , 2 , 3 , 4 , 5 ]. Tin-based perovskite solar cells (TPSCs) show significant potential owing to their planar device structure, low-temperature solution fabrication process, and potential applications in flexible and tandem devices [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

Advanced Strategies to Tailor the Nucleation and Crystal Growth in Hybrid Halide Perovskite Thin Films

“…These methods involve changing the perovskite precursor solution concentration and temperature, optimizing the coating parameters such as the spin speed and time, tuning the annealing temperature of thin films. In addition to these methods, new techniques such as composition ( Kang and Park, 2019 ) and thermal engineering ( Srivastava et al, 2018 ), additive engineering in the perovskite precursor solution ( Tavakoli et al, 2019 ; Giuliano et al, 2021 ; Zhang et al, 2021 ), air-assisted drying ( Ding et al, 2019 ), humidity tuning ( Gangishetty et al, 2016 ), vapor-assisted annealing ( Sheng et al, 2015 ; Shi et al, 2015 ; Karlsson et al, 2021 ), and surface passivation layer capping ( Chen P. et al, 2018 ; Tavakoli et al, 2019 ; He et al, 2020 ; Yu et al, 2021 ) are also employed. To gain a deeper insight into this, we need to understand film optimization through the process of the crystal growth and design.…”