Platform for multisCale simulation of hot carriers: electrons and phonons for energy harvesting – PlaCho

The project Placho (Platform for multisCale simulation of hot carriers: electrons and phonons for energy harvesting) aims to develop an original multi scale (DFT+Monte Carlo+NEGF) numerical platform from atoms to device specifically dedicated to energy conversion. This versatile tool based on first principles will be able to capture the properties of electrons, holes and phonons and their coupling in a wide energy range for a large set of materials without the need of prior measurements. The fine accuracy of physical description of electric and thermal phenomena will be exploited for device simulation purposes. The transport of carriers belonging to the high energy distribution tail in both the stationary and transient regimes will be considered also when quantum effects are dominant. The output of the PlaCho project will boost the evaluation of the potentiality and the optimization of emerging concepts in energy conversion in which band engineering for high energy filtering, tunneling and high energy carrier extraction are involved for, but not limited to, thermoelectrics and photovoltaics.

The consortium will be composed by 3 partners C2N, LSI and IMPMC with complementary expertise on DFT for electrons, DFPT for phonons and transport and device simulation. The project is organized into one management (WP0) and four scientific (WP1-3) WorkPackages. WP1 is dedicated to DFT calculations and aims at describing properties of electrons, holes and phonons in a large energy range for different type of materials. Both WP2 and WP3 deal with the transport of hot carriers in terms of DFT based semi-classical and quantum formalisms, respectively. In WP4 which is the achievement of the project, PV and TE energy converters in which hot carriers are important will be simulated by combining others WP developments.

In the short term, the cross-cutting collaboration will significantly enhance the scientific and technical understanding of the fundamentals of physics of hot carriers that can be used in energy harvesters. Our ambition is first to provide to the community the best of academic modeling capability in the field of energy conversion device simulation. To the best of our knowledge, advanced simulation tools coupling DFT, full band NEGF and MC have never been developed for studying hot carriers: electrons, holes, phonons and their coupling. This objective can be achieved only by combining the complementary skills of the consortium. Thus, the outcomes of this project will constitute a breakthrough in the community of energy converter device physics. Secondly, the ab-initio modeling of phonon/phonon and electron/phonon coupling remains a challenge. The PlaCho project aims at developing new methodologies in order to extend the capability of previous first principle approaches. Thirdly, parametrizing semi-empirical thermal and electric simulations with ab-initio calculations will open the way to the exploration of many different devices made of various materials, involving nanostrutures of different shape. Out of equilibrium effects, quantum effects and transient effects could be efficiently and accurately investigated to optimize the energy conversion. Finally, a totally new simulation method solving the quantum transport problem using a merely ab-initio description of the materials (without the need of intermediate semi-empirical parameters) will be developed within the project.

In the medium/long term, PlaCho will open new avenues for the technological development and optimisation of novel devices exploiting the hot carrier properties. Through the development of innovative energy harvester with tailored properties, the overall impact of PlaCho will be the major societal needs for energy management once these emerging technologies will be transferred to the industrial domain.