Optical cooling by interfacial charge transfer in 2D heterostructures

Researchers demonstrated optical cooling in two-dimensional semiconductor heterostructures on June 24, 2026, utilizing phonon-assisted interfacial charge transfer. This method allows for cryogen-free thermal management, bypassing the need for stringent quantum-efficiency requirements typically associated with optical cooling techniques. The study, published in Nature, details how energy is dissipated as heat through the transfer of charge carriers across the interface of stacked 2D materials. This process effectively lowers the temperature of the heterostructure without external refrigeration systems. The findings present a novel approach to thermal management for sensitive electronic and photonic devices, potentially reducing operational costs and complexity. The technique's efficiency is linked to the specific phonon modes present at the interface and the electronic band alignment of the constituent 2D materials, such as transition metal dichalcogenides. This breakthrough could pave the way for more compact and efficient cooling solutions in various technological applications.