Researchers have developed lead-free tin halide perovskite solar cells that achieve a 16.2% power conversion efficiency and maintain operational stability beyond 1,000 hours at 55 °C, according to a study published in Nature Materials.
Tin halide perovskites provide narrower bandgaps and improved environmental safety compared to widely studied lead-based alternatives, but air sensitivity has historically limited their practical use. To address this vulnerability, the team introduced a 4-chloro-phenethylammonium (4ClPEA) organic cation to create ultrastable two-dimensional and quasi-two-dimensional perovskite structures.
The chlorinated cation creates tighter interlayer packing and stronger π-stacking interactions in (4ClPEA)2SnI4 compared to other (4XPEA)2SnI4 structures containing hydrogen, fluorine, or bromine. These structural characteristics substantially impede the diffusion of oxygen and water, allowing the material to retain bright photoluminescence for several months in ambient air.
Adding 4ClPEA also improves the crystallinity and orientation of 2D/3D tin halide perovskite films. This structural alignment enabled the 16.2% efficiency rating while delivering prolonged storage durability alongside high-temperature operational endurance.
Christopher T. Triggs, Lei Chen, Kai Zhu, and Song Jin filed US patent application number US64/048,398 based on the research. The investigation included collaborators across the University of Wisconsin–Madison, the National Laboratory of the Rockies, the University of Toledo, and the University of Colorado Boulder, with crystallographic data deposited under Cambridge Crystallographic Data Centre numbers 2496775–2496777 and 2538309.
