Thermal Management and Hot Carrier Multiplication in Few Layered PtSe₂ Devices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials are crucial for next-generation electronics, requiring optimized thermal transport and high current capacity.
• Transition metal dichalcogenides (TMDs), like PtSe2, offer tunable electronic properties and are vital for understanding electron-phonon interactions and thermal transport.
• PtSe2 transitions from semimetal to semiconductor from bulk to monolayer, making it a promising material for electronic devices.

Purpose of the Study:

• Investigate the high electric field breakdown behavior of few-layered PtSe2 devices.
• Understand the heat dissipation mechanisms in PtSe2-based devices at low and room temperatures.
• Analyze the interfacial thermal conductivity of PtSe2/SiO2 and PtSe2/h-BN interfaces.

Main Methods:

• Raman thermometry was employed to quantitatively measure interfacial thermal conductivity.
• Electrical breakdown characteristics of PtSe2 devices were studied at room temperature.
• Magneto-transport measurements on PtSe2 Hall bar devices were conducted at low temperatures.

Main Results:

• Interfacial thermal conductivity values of 14.2 MW.m⁻².K⁻¹ (PtSe2/SiO2) and 30.5 MW.m⁻².K⁻¹ (PtSe2/h-BN) were determined.
• Self-heating effects were identified as the primary cause of electrical breakdown at room temperature.
• Carrier multiplication under high electric fields was observed at low temperatures, leading to superlinear current response and breakdown.

Conclusions:

• Self-heating is a critical factor limiting the performance of PtSe2 devices at room temperature.
• Carrier multiplication is the dominant mechanism for electrical breakdown in PtSe2 at low temperatures.
• Understanding these breakdown mechanisms is essential for designing high-performance 2D heterogeneous electronics.