Exciton-Plasmon Driven Hot Carriers' Extraction in Cu_2-xS/WS₂ Heterostructure

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Hot charge carrier extraction is key for improving light-driven optoelectronic devices.
• Two-dimensional transition metal chalcogenides (TMCs) offer high-energy excitons.
• Plasmonic materials generate hot charge carriers.

Purpose of the Study:

• To synthesize a semiconductor plasmonic-2D heterostructure (Cu₂₋ₓS/WS₂) for synergistic energy utilization.
• To investigate the transfer of plasmon-generated hot charge carriers and excitons within the heterostructure.
• To explore the potential for enhanced hot carrier-based optoelectronic devices.

Main Methods:

• Synthesis of Cu₂₋ₓS/WS₂ semiconductor plasmonic-2D heterostructures.
• Ultrafast transient absorption spectroscopy under 840 nm photoexcitation.
• Analysis of charge carrier and exciton dynamics under resonant and nonresonant excitation.

Main Results:

• Efficient transfer of plasmon-generated hot holes from Cu₂₋ₓS to WS₂ was confirmed.
• Hot electrons from WS₂ excitonic states were observed to transfer to Cu₂₋ₓS.
• Demonstrated synergistic harnessing of LSPR-generated hot carriers and TMC excitons.

Conclusions:

• Semiconducting plasmonic-2D heterostructures show promise for optoelectronic applications.
• Efficient utilization of both hot charge carriers and high-energy excitons is achievable.
• This approach paves the way for advanced hot carrier-based optoelectronic devices.