Large-Area Bi₂O₂Se Nanosheets With Enhanced Optoelectronic Performance for Flexible Electronics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Flexible electronics require materials with high electrical and optoelectronic performance and mechanical durability.
• Bismuth oxyselenide (Bi2O2Se) offers high carrier mobility and excellent optoelectronic properties but faces challenges in large-area synthesis.
• Conventional low-pressure chemical vapor deposition (LPCVD) limits scalability and growth conditions for Bi2O2Se nanosheets.

Purpose of the Study:

• To develop a scalable method for synthesizing large-area, high-quality Bi2O2Se nanosheets.
• To investigate the growth mechanisms and key parameters for large-domain Bi2O2Se formation.
• To evaluate the electronic and mechanical properties of Bi2O2Se nanosheets for flexible device applications.

Main Methods:

• Synthesis of Bi2O2Se nanosheets using atmospheric pressure chemical vapor deposition (APCVD).
• Systematic investigation of growth parameters and mechanisms.
• COMSOL simulations to model adatom diffusion on the substrate surface.
• Fabrication and testing of devices on flexible substrates.

Main Results:

• Achieved millimeter-scale Bi2O2Se nanosheets with domain sizes up to 0.4 mm using APCVD.
• Identified key factors enabling large-domain formation through parameter studies and simulations.
• Demonstrated excellent electronic transport properties with room-temperature carrier mobility of 110 cm2V-1s-1 and low-temperature mobility exceeding 3700 cm2V-1s-1.
• Flexible devices maintained stable performance under repeated mechanical bending.

Conclusions:

• APCVD is a viable and scalable method for producing large-domain Bi2O2Se nanosheets.
• The synthesized Bi2O2Se nanosheets possess superior electronic and mechanical properties suitable for flexible electronics.
• This work establishes a promising platform for next-generation flexible electronic and optoelectronic technologies.