In this WP, we will explore the electronic and lattice temperatures in the asymmetric double barrier (ADB) heterostructure (see task 1). The aim is to determine the general physical parameters providing the highest temperature reduction. Based on simulation’s guidance, we will investigate the interplay between lattice and electron refrigeration and will operate a comprehensive optimization procedure by modifying three main parameters: i) thickness of the emitter barrier (LEmit) which determines the resonant tunneling injection; ii) the QW thickness (LQW) and the height of the collector barrier, which both determine the activation energy W at the origin of the evaporative cooling processes; iii) the external temperature (from 4K to 300K) since evaporative and thermionic refrigeration’s depend on electron distribution and phonon absorption respectively, two parameters directly depending on thermal energy.
From the theoretical side, we will adopt a multi-physics modeling approach combining sophisticated quantum transport codes, to obtain a precise prescription for the optimization of the device performance, and more compact model based on the rate equation model to provide a more intuitive and analytical understanding on the physics.
From the experimental side, temperature will be determined by photoluminescence (PL) both using the high energy slopes of the PL spectra and the whole PL spectrum. This latter technique has recently been suggested and specifically adapted to study hot-carrier solar cells [Ngu2018]. It results a great precision improvement of the temperature measurement.