Large-Area Monolayer p-Type Semiconductor Films Toward High-Performance Electrical Device Arrays

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) semiconductors offer solutions for post-Moore computing due to their atomic thickness and immunity to short-channel effects.
• A significant challenge remains in producing large-area, high-quality monolayer p-type 2D semiconductors.

Purpose of the Study:

• To develop a method for controlled nucleation to synthesize large-area, uniform monolayer p-type 2D semiconductors.
• To investigate the electrical properties of synthesized tungsten diselenide (WSe2) and Nb-incorporated WSe2 films.

Main Methods:

• Controlled nucleation of p-type WSe2 by tuning selenium precursor evaporation areas.
• Optimization of nucleation density for centimeter-scale film synthesis.
• Fabrication and characterization of field-effect transistor arrays.

Main Results:

• Centimeter-scale uniform monolayer WSe2 and Nb-incorporated WSe2 films were successfully synthesized.
• WSe2 films exhibited p-type behavior with hole mobilities of 34 ± 17 cm²/V·s and an on/off ratio of 4 × 10⁷.
• Nb incorporation enhanced hole mobility to 48 ± 16 cm²/V·s with an on/off ratio of ≈10⁸.

Conclusions:

• The controlled nucleation strategy enables the scalable synthesis of uniform 2D p-type semiconductors.
• Synthesized WSe2 films demonstrate potential for use in electrical devices and integrated circuits.
• Nb incorporation further improves the performance of 2D p-type semiconductors for electronic applications.