Researchers from China's Westlake University, Zhejiang University, Binzhou University and U.S-based Purdue University have reported the synthesis of a series of 2D tin perovskite bulk crystals with high phase purity via a mixed-solvent strategy.
Ruddlesden-Popper tin halide perovskites are a class of two-dimensional (2D) semiconductors with exceptional optoelectronic properties, high carrier mobility, and low toxicity. However, the team aimed to address the issue of their challenging synthesis and the lack of fundamental understanding of their optoelectronic properties (compared to their lead counterparts).
By engineering the quantum-well thickness (related to n value) and organic ligands, the optoelectronic properties, including photoluminescence emission, exciton-phonon coupling strength, and exciton binding energy, exhibited a wide tunability.
In addition, these 2D tin perovskites exhibited excellent lasing performance. Both high–n value tin perovskite (n > 1) and n = 1 tin perovskite thin flakes were successfully optically pumped to lase.
Furthermore, the lasing from 2D tin perovskites could be maintained up to room temperature.
The scientists noted that further efforts are still needed to optimize the cavity geometry (tailoring the size and shape of the thin flakes) while maintaining high phase purity and to gain deeper understanding of the correlations between crystal structure, lattice, carrier dynamics, and lasing performance. The ease of lasing from 2D tin halide perovskites and their high working stability highlight the prospect of RP tin perovskite flakes in future microlasers and integrated nanophotonics.