Antioxidative 2D Bismuth Selenide via Halide Passivation for Enhanced Device Stability

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) bismuth selenide (Bi2Se3) is a topological insulator with unique electronic properties, making it attractive for electronic devices.
• Bi2Se3 is highly susceptible to oxidation, posing a significant challenge for its practical application.
• Existing surface passivation methods are often time-consuming and technically demanding, necessitating in situ passivation strategies.

Purpose of the Study:

• To investigate the role of halide anions (Cl-, Br-, I-) in the electrochemical intercalated exfoliation of Bi2Se3 nanosheets.
• To determine the antioxidation capacity of Bi2Se3 nanosheets prepared using different halide anions.
• To enhance the stability of 2D Bi2Se3 nanosheets for electronic device applications.

Main Methods:

• Electrochemical intercalated exfoliation of Bi2Se3 nanosheets in solutions containing different halide anions (Cl-, Br-, I-).
• Investigation of the chemical properties and surface bonding of the synthesized Bi2Se3 nanosheets.
• Evaluation of the oxidation resistance and device stability of the prepared Bi2Se3 nanosheets.

Main Results:

• Bi2Se3 nanosheets synthesized using tetrabutylammonium chloride (TBA+ and Cl-) exhibited superior oxidation resistance compared to those prepared with bromide or iodide.
• The enhanced antioxidation is attributed to the formation of surface bonds between bismuth (Bi) and chloride (Cl) atoms.
• Improved oxidation resistance directly correlates with enhanced stability in Bi2Se3-nanosheet-based electronic devices.

Conclusions:

• Halide anions, particularly chloride, play a crucial role in improving the chemical stability and antioxidation capacity of electrochemically exfoliated Bi2Se3 nanosheets.
• Surface bonding of Bi with Cl is a key mechanism for achieving enhanced oxidation resistance.
• This study provides a pathway for optimizing electrolyte composition to improve the performance and longevity of 2D Bi2Se3 electronic devices.