Thanks to the in-depth study the ADB heterostructure in task 2, task 3 will be dedicated to the conception and fabrication of disruptive cooling devices. Three structures will be investigated, each of them assessing a specific physical cooling effect:


Objective 3.1: “Quantum cascade cooler (QCC)”

A superlattice heterostructure can drastically improve the cooling power. We propose a device which consists of sequentially stacked thermionic emission structures. Thanks to appropriate band engineering, it is possible to progressively increase the energy level in each GaAs QW (Fig. 1-a)). In this case, an electron absorbing a phonon in the first period can tunnel into the next period of the structure, where another phonon can be absorbed as shown in the current spectrum of Figure 1-b).


Objective 3.2: hybrid (metal-semiconductor) structure

More details in a near future.


Objective 3.3: opto-thermionic pumping

More details in a near future.