Laser Cooling in Semiconductor Heterojunctions by Extraction of Photogenerated Carriers

Abstract

η rad φ in (E) Laser cooling of a semiconductor material, in which heat is extracted by emitting photons, requires a near-perfect external radiative efficiency. In this theoretical work, we propose a cooling system based on carrier extraction in a large gap reservoir. The electron-hole pairs generated in the material to be cooled are extracted in such a reservoir by absorbing phonons, then carrying a heat flux. With an analytical detailed balance model, we show that this concept is applicable even in materials with moderate external radiative efficiency. Moreover, by adjusting the gap of the reservoir to the laser power, this system can either reach high efficiency or transfer high power with lower efficiency.

Solar Refrigeration Based on Impact Ionization in a Transition Metal Dichalcogenides Superlattice

“…These expressions are based on a three-dimensional (3D) description of the Landauer approach and use the 3D density-of-states in the reservoirs and the effective mass ( m *) approximation. They have been derived in a previous work . As J contact and P contact are proportional to m *, we use the limiting (smallest) effective mass for the implementation.…”

“…The radiative process causing optical refrigeration generally requires materials with radiative efficiency close to 1. , To overcome this requirement and based on the principle of evaporative cooling, we previously showed that extracting the photogenerated carriers into a larger bandgap reservoir generates cooling even with modest radiative efficiencies . Such a device requires a type I heterojunction, as shown in Figure .…”