Electrically Tunable Tunneling and Spectral Response in WSe₂/h-BN/CdSe/Graphene Heterostructure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Mixed-dimensional heterostructures combining 0D and 2D materials offer tunable optical properties for optoelectronics.
• Bias-induced methods can further tune optical properties beyond intrinsic band alignment in van der Waals junctions.

Purpose of the Study:

• To investigate bias-induced tunneling characteristics in vertically stacked WSe2/h-BN/CdSe quantum dots/graphene heterostructures.
• To demonstrate voltage-dependent control of carrier dynamics and optical properties in these mixed-dimensional devices.

Main Methods:

• Fabrication of vertically stacked WSe2/h-BN/CdSe quantum dots/graphene heterostructures.
• Electrical analysis using Simmons approximation to study carrier transport through h-BN barrier.
• Spectral responsivity and scanning photocurrent measurements to observe tunneling-induced exciton dissociation.

Main Results:

• Demonstrated tunneling-mediated charge transfer through thin h-BN layers.
• Showcased bias-dependent modulation of the barrier height.
• Observed tunneling-induced exciton dissociation in WSe2 and CdSe quantum dots.

Conclusions:

• Established a voltage-dependent tunneling platform for mixed-dimensional optoelectronic devices.
• Enabled deterministic control of carrier dynamics via electrical bias.
• Highlighted the potential of such heterostructures for advanced optoelectronic applications.