CH3NH3SnxPb1-xBr3 hybrid perovskite solid solution: synthesis, structure, and optical properties

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photovoltaics

Background:

• Methylammonium lead halide perovskites are promising photovoltaic materials.
• Tuning the band gap of perovskites is crucial for optimizing solar cell performance.
• Incorporating tin into lead halide perovskites offers a pathway to narrower band gaps.

Purpose of the Study:

• To synthesize and characterize a series of methylammonium tin-lead bromide (MASnxPb1-xBr3) solid solutions.
• To investigate the structural and optical properties of these solid solutions.
• To determine the relationship between tin content and band gap energy.

Main Methods:

• Solid-state synthesis of MASnxPb1-xBr3 with varying tin fractions (x).
• X-ray diffraction (XRD) for structural characterization and unit cell determination.
• Optical spectroscopy to measure the band gap energy.

Main Results:

• Successfully synthesized single-phase MASnxPb1-xBr3 solid solutions with homogeneous tin/lead distribution.
• All synthesized materials adopted a cubic crystal structure.
• Unit cell volume decreased linearly with increasing tin content, following Vegard's law.
• Band gap energy tuned linearly from 2.20 eV (x=0) to 1.33 eV (x=1), following Vegard's law.
• Extended light absorption into the near-infrared region.

Conclusions:

• MASnxPb1-xBr3 solid solutions can be synthesized with controlled tin incorporation.
• The structural and optical properties of these materials are tunable via tin content.
• These findings demonstrate the potential of tin-containing perovskites for near-infrared light harvesting applications.