Profile
Self-motivated university graduate with a Msc in Condensed Matter physics from the University Of Dschang, Cameroon where I have worked on ‘Cumulative Effect of Rashba, Dresselhaus and Zeeman Effects on the Polaron in a Quantum Dot‘. We investigated the competitive influence of the Rashba, the Dresselhaus and the Zeeman effects on the polaron’s properties in an asymmetric quantum dot within the improved linear combination operator method and the Pekar type variational method. We discussed the behaviour of the polaron effective mass and ground state energy. In May 2017, I have participated at the international conference Quantum Africa 4, held in Tunisia where I have presented my Msc work.
I am currently a PhD student at the ICN2 (Catalan Institute of Nanoscience and Nanotechnology). I have received the grant innovation programme under the Marie Skłodowska-Curie grant agreement No. 754558 which has allowed me to embrace a new field and developed gradually my expertise and experience in programming, Density Functional Theory, ab-intio Molecular Dynamics to name only those. I am currently working on defects in amorphous structure.
After obtaining my MSc in Condensed Matter in Physics in Cameroon, I got a scholarship to join the AIMS (African Institute of Mathematical Sciences) where I worked on ‘Cold Atoms Transport in a Ratchet Optical Lattice Potential’. The goal of the essay was to develop a directed transport model of particles trapped in a potential which is generated by two counter-propagating lasers. This work gave us a better understanding of the transport phenomena in cellular scale and brownians motors.
Afterward, I got a new scholarship to join the ICTP in Italy, where I worked on ‘Density Fluctuations in a Lennard-Jones Liquid’ this work has helped in identifying in a Lennard-Jones liquid more spherical than fractal-like voids.
During this academic course, I have attending the DIPC School on Photo and ElectroCatalysis at the Atomic Scale in San Sebastian. One workshop: “Tutorial on Writing reproductible workflows for computational materials science” EPFL, Lausanne. I have participated in 2 conferences with a talk on Electronic structure and localized states in a-GeSe, July 1st 2020 and Approaching electrochemistry with TranSIESTA, Operando Surface Science – Atomistic insights into electrifiedsolid/liquid interfaces, Bad Honnef, Germany, 09-13/12/19
Project
Defects in amorphous GeSe
The industry-wide acceptance of resistive memories (RRAM,PCM, STTRAM) as a separate Storage Class Memory (SCM) concept will require the use of series-connected current-limiting two-terminal device, the so-called selector. Its role is to suppress the unselected shunt path for the leakage current in a large (Gbit) arrays, which otherwise presents a huge reliability issue. The selector should have a low OFF leakage and a high ON current, with a half-bias non-linearity larger than 10^4.
To achieve that, the Ovonic Threshold Switching (OTS) materials are among most promising. DFT level simulations will be used to investigate the nature of the conductive traps in the OTS amorphous material, the effects of material and defect parameters on the GeSe OTS selector current performances, i.e. maximum current and current non-linearity. In particular, disordered models for OTS chalcogenide material systems will be generated and validate using Decorate-and-Relax (from the work of IMEC) for starting configuration and subsequent Melt-and-Quench technique. Various dopants (Si, S, P, Te, As) and concentrations (1%, 3%,5%, 7%, 10%, 15%), and different OTS chalcogenide stoichiometry (Ge60Se40 /Ge50Se50 /Ge40Se60) will be considered. Material (e.g. mobility gap) and defect parameters (thermal ionization andrelaxation energies, formation enthalpy and energy, and diffusion barrier) will be calculated.
This work is a part of the Interoperable material-to-device infrastructure (IM2D), which is an effort to provide a solution for industry-ready software, which upscales the parameters from DFT results and eventually will be used in device simulations. The above-calculated material (e.g. mobility edge) and defect properties (density, energies) will be subsequently used as input for the device cycle in IM2D, to project the electrical performances and reliability of GeSe selectors by considering different electrode materials.
