A fabrication process for flexible single-crystal perovskite devices.

Area of Science:

• Materials Science
• Solid-State Physics
• Optoelectronics

Background:

• Organic-inorganic hybrid perovskites are promising for electronic and optoelectronic devices.
• Single-crystal perovskites offer superior carrier transport and stability compared to polycrystalline forms.
• Fabricating controlled single-crystal perovskites with desired morphology and composition remains a significant challenge.

Purpose of the Study:

• To develop a novel method for fabricating high-quality single-crystal hybrid perovskites on arbitrary substrates.
• To achieve precise control over the thickness, area, and composition gradient of these single crystals.
• To demonstrate the potential of these engineered perovskites in advanced device applications.

Main Methods:

• A solution-based lithography-assisted epitaxial growth and transfer technique was employed.
• Precise control over thickness (600 nm to 100 µm) and area (up to 5.5 cm x 5.5 cm) was achieved.
• Compositional gradients, such as from methylammonium lead iodide (MAPbI3) to MAPb0.5Sn0.5I3, were engineered in the thickness direction.

Main Results:

• Fabricated single-crystal hybrid perovskites exhibit quality comparable to those grown on epitaxial substrates.
• The method allows for mechanically flexible perovskite films, dependent on thickness.
• Lead-tin gradient alloying resulted in a graded electronic bandgap, enhancing carrier mobility and reducing recombination.

Conclusions:

• The developed method provides a versatile platform for fabricating tailored single-crystal hybrid perovskites.
• These perovskites demonstrate high stability and performance in devices, exemplified by solar cells achieving 18.77% efficiency.
• This advancement opens new avenues for designing next-generation flexible and stable optoelectronic devices.