Improved Efficiency in WSe₂ Solar Cells Using Amorphous InO Heterocontacts.

Area of Science:

• Materials Science
• Optoelectronics
• Renewable Energy

Background:

• Van der Waals (vdW) layered materials possess promising optoelectronic properties for photovoltaic applications.
• Current vdW solar cell efficiencies are low and often lack statistical validation or detailed spectral analysis.

Purpose of the Study:

• To fabricate and characterize a van der Waals solar cell using a p-type WSe2 absorber.
• To provide statistical data and spectral quantum efficiency analysis for vdW solar cells.
• To establish a new benchmark efficiency for vdW material-based solar cells.

Main Methods:

• Fabrication of a solar cell device utilizing a p-type tungsten diselenide (WSe2) absorber layer.
• Integration of a transparent indium oxide (InO2) front electron contact and a palladium (Pd) rear reflector/hole contact.
• Performance characterization of multiple devices under standard test conditions (AM 1.5G, 1 sun).

Main Results:

• Achieved an average 1 sun conversion efficiency exceeding 5% across 10 fabricated devices.
• A champion device demonstrated a record power conversion efficiency of 6.37%.
• External quantum efficiency analysis confirmed current density and showed near-unity quantum efficiency around 600 nm.

Conclusions:

• This work establishes a new highest efficiency for van der Waals solar cells.
• The results support the consideration of vdW materials as viable candidates for next-generation thin-film solar cells.
• Statistical data and spectral analysis provide robust evidence for the performance of these devices.