Tailoring amorphous boron nitride for high-performance two-dimensional electronics

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Two-dimensional (2D) materials possess unique electronic and optoelectronic properties crucial for next-generation devices.
• Achieving high performance in 2D material devices is hindered by challenges in forming uniform dielectric layers and preventing interfacial defects.
• Precise control over the dielectric environment is essential for unlocking the full potential of 2D materials.

Purpose of the Study:

• To demonstrate a scalable, low-temperature atomic layer deposition (ALD) process for synthesizing uniform amorphous boron nitride (aBN) thin films on 2D materials.
• To evaluate the impact of aBN dielectric layers on the electronic and optoelectronic properties of molybdenum disulfide (MoS2) based devices.
• To overcome the limitations of current dielectric integration methods for 2D materials.

Main Methods:

• Utilized atomic layer deposition (ALD) at low temperatures (<250°C) to synthesize amorphous boron nitride (aBN) thin films.
• Employed a seed-free ALD approach to achieve uniform and conformal aBN dielectric layers on 2D material surfaces.
• Fabricated multiple quantum well structures and double-gated monolayer MoS2 field-effect transistors with aBN dielectrics.

Main Results:

• Achieved wafer-scale synthesis of uniform, conformal aBN thin films with high oxidative stability.
• Demonstrated excellent dielectric strength of 8.2 MV/cm for the synthesized aBN films.
• Showcased the successful integration of aBN dielectrics in MoS2-based devices, enabling evaluation of their optoelectronic and electronic properties.

Conclusions:

• The developed low-temperature, seed-free ALD process enables scalable integration of high-quality aBN dielectrics for 2D materials.
• This advancement addresses critical challenges in dielectric integration, paving the way for improved 2D material device performance.
• The findings facilitate the realization of theoretical performance limits in next-generation 2D electronics and photonics.