Unveiling Intrinsic Bulk Photovoltaic Effect in Atomically Thin ReS₂

Area of Science:

• Solid State Physics
• Materials Science
• Renewable Energy

Background:

• The bulk photovoltaic effect (BPVE) presents a potential pathway to overcome current solar cell efficiency limits.
• Differentiating intrinsic BPVE from extrinsic photocurrent contributions is a critical challenge in solar cell research.

Purpose of the Study:

• To fabricate high-quality lateral devices using atomically thin ReS2 to isolate and study intrinsic BPVE.
• To distinguish intrinsic bulk photovoltaic signals from extrinsic interfacial photocurrent contributions.
• To establish a platform for investigating BPVE in other noncentrosymmetric van der Waals materials.

Main Methods:

• Fabrication of lateral devices using high-quality, atomically thin ReS2 with minimized contact resistance.
• Experimental measurement of photocurrent and responsivity.
• Theoretical calculations to support experimental findings.

Main Results:

• Demonstrated devices exhibit significant intrinsic bulk photovoltaic performance.
• Achieved intrinsic responsivities of approximately 1 mA/W in the visible spectrum.
• Successfully distinguished intrinsic BPVE signals without external tuning methods like strain engineering.

Conclusions:

• The developed ReS2 lateral devices provide an optimal platform for studying intrinsic BPVE.
• The findings validate the potential of BPVE in advancing solar cell efficiency.
• The methodology is applicable to other noncentrosymmetric van der Waals materials for next-generation light-harvesting devices.