Heteroepitaxial Strain Engineering and Interfacial Energy Transfer Boosting Optoelectronic Properties in C₆₀/WS₂ van...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Van der Waals (vdW) heterostructures enable tailored optoelectronic properties at heterointerfaces.
• Combining molecular semiconductors and atomically flat nanomaterials is key to novel device functionalities.

Purpose of the Study:

• To investigate the heteroepitaxial assembly of C60 molecules on monolayer tungsten disulfide (ML-WS2).
• To explore the impact of anisotropic compression strain on C60 lattice and optical transitions.
• To enhance the optoelectronic performance of C60/ML-WS2 heterostructures.

Main Methods:

• Heteroepitaxial assembly of C60 on ML-WS2.
• Characterization of C60 lattice strain and optical transitions.
• Fabrication and testing of C60/ML-WS2 transistors.
• Measurement of photoluminescence (PL) intensity, charge carrier mobility, photoresponsivity, and detectivity.

Main Results:

• Anisotropic compression strain in C60 induced 1D polymeric C60 strings and activated symmetry-forbidden optical transitions.
• A 310% enhancement in PL intensity was observed due to interfacial energy transfer from ML-WS2 to C60.
• C60/ML-WS2 transistors achieved a charge carrier mobility of 10.4 cm2 V-1 s-1 and an ultralow 230 meV contact barrier.
• Devices demonstrated superior photoresponsivity (46.4 A W-1) and detectivity (3.6 × 1012 Jones).

Conclusions:

• Engineered C60/ML-WS2 heterostructures exhibit significantly enhanced optoelectronic properties compared to pristine ML-WS2.
• The formation of 1D polymeric C60 strings and interfacial energy transfer are crucial for performance enhancement.
• These findings pave the way for advanced applications in optoelectronics and photodetectors.