A low-bandgap (1.33 eV) Sn-based MA FA Pb Sn I perovskite is developed via combined compositional, process, and interfacial engineering. It can deliver a high power conversion efficiency (PCE) of 14.19%. Finally, a four-terminal all-perovskite tandem solar cell is demonstrated by combining this low-bandgap cell with a semitransparent MAPbI cell to achieve a high efficiency of 19.08%.
Resolving the structure−property relationships of twodimensional (2D) organic−inorganic hybrid perovskites is essential for the development of photovoltaic and photoelectronic devices. Here, pressure (0−10 GPa) was applied to 2D hybrid perovskite flakes mechanically exfoliated from butylammonium lead halide single crystals, (C 4 H 9 NH 3 ) 2 PbI 4 , from which we observed a series of changes of the strong excitonic emissions in the photoluminescence spectra. By correlating with in situ high-pressure X-ray diffraction results, we examine successfully the relationship between structural modifications in the inorganic PbI 4 2− layer and their excitonic properties. During the transition between Pbca (1b) phase and Pbca (1a) phase at around 0.1 GPa, the decrease in ⟨Pb−I−Pb⟩ bond angle and increase in Pb−I bond length lead to an abrupt blue shift of the excitonic bandgap. The presence of the P2 1 /a phase above 1.4 GPa increases the ⟨Pb−I−Pb⟩ bond angle and decreases the Pb−I bond length, leading to a deep red shift of the excitonic bandgap. The total band gap narrowing of ∼350 meV to 2.03 eV at 5.3 GPa before amorphization, facilitates (C 4 H 9 NH 3 ) 2 PbI 4 as a much better solar absorber. Moreover, phase transitions inevitably modify the carrier lifetime of (C 4 H 9 NH 3 ) 2 PbI 4 , where an initial 150 ps at ambient phase is prolongated to 190 ps in the Pbca (1a) phase along with enhanced photoluminescence (PL), originating from pressure-induced strong radiative recombination of trapped excitons.The onset of P2 1 /a phase shortens significantly the carrier lifetime to 53 ps along with a weak PL emission due to pressure-induced severe lattice distortion and amorphization. High-pressure study on (C 4 H 9 NH 3 ) 2 PbI 4 nm-thin flakes may provide insights into the mechanisms for synthetically designing novel 2D hybrid perovskite based photoelectronic devices and solar cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.