Mikaël Kepenekian

CNRS Researcher

Email : mikael [dot] kepenekian [at] univ-rennes1 [dot] fr

Phone : +33 (0) 2 23 23 31 59

Office number : Beaulieu - Building 10B - 217

Research activity

I am a computational chemist dedicated to the investigation of compounds (molecules or solids) exhibiting magnetic, electronic or optical properties with various tools ranging from wavefunction-based multireference approaches (e.g. CASSCF), density functional theory (DFT) based calculations or non-equilibrium Green's functions (NEGF).

My activity currently focus on 3 topics:

Halide perovskites for optoelectronics applications

Halide hybrid perovskites have become a hot topic in the last few years, primarily due to their undeniable breakthrough in photovoltaic research and development with solar-to-electricity conversion efficiency records that went from 3.8% to over 24% [see NREL chart]. Halide perovskites come in many flavors (3-dimensional, 2-dimensional, colloidal nanostructures). Prior to that craze, the layered form of halide perovskites were the star of the family thanks to the great photophysical properties they exhibit. My work focus on the electronic, optical and transport properties of 3D and layered perovskites that are rationalized thanks to concepts of solid-state chemistry and physics.

Layered halide perovskites: properties and applications

Selected publications

Concept of lattice mismatch and emergence of surface states in 2D hybrid perovskite quantum wells
M. Kepenekian, B. Traore, J.-C. Blancon, L. Pedesseau, H. Tsai, W. Nie, C. C. Stoumpos, M. G. Kanatzidis, J. Even, A. D. Mohite, S. Tretiak, C. Katan
Nano Lett. 201818, 5603

Extremely efficient internal exciton dissociation through edge-states in layered 2D perovskites for high-efficiency optoelectronic devices
J.-C. Blancon, H. Tsai, W. Nie, C. C. Stoumpos, L. Pedesseau, C. Katan, M. Kepenekian, K. Appavoo, M. Y. Sfeir, S. Tretiak, M. G. Kanatzidis, J. Even, J. J. Crochet, A. D. Mohite
Science 2017355, 1288

Rashba and Dresselhaus effects in hybrid organic-inorganic perovskites: from basics to devices
M. Kepenekian, R. Robles, C. Katan, D. Sapori, L. Pedesseau, J. Even
ACS Nano 201512, 11557

Supported functional molecules and networks

Ever since the fundamental work of Aviram and Ratner [Chem. Phys. Lett. 197429, 277], the aspiration to susbstitute functional molecules to silicon-based devices has generated a whole new topic for physicists and chemists. Inorganic chemistry has produced a wealth of functional molecules presenting optic, magnetic or electronic activity. By supporting those molecules one can form a molecular device and perform logic operations. Here, organometallic compounds are associated with mettalic or semiconductor surfaces and inspected by DFT approaches and NEGF subsequent treatments.

Supported Mo-based cluster Selected publications

Red-NIR luminescence of Mo6 monolayered assembly directly anchored on Au(001)
M. Kepenekian, Y. Molard, K. Costuas, P. Lemoine, R. Gautier, S. Ababou-Girard, B. Fabre, P. Turban, S. Cordier
Mater. Horizons 20196, 1828
Front cover of issue 9 (November 2019)

Towards highly cooperative spin-crossover metal-organic frameworks on metallic surfaces
T. Groizard, N. Papior, B. Le Guennic, V. Robert, M. Kepenekian
J. Phys. Chem. Lett. 20178, 3415

Difficulties in the ab-initio description of electron transport through spin filters
M. Kepenekian, J.-P. Gauyacq, N. Lorente
J. Phys.: Condens. Matter 201426, 104203

Classical semiconductors

The electronic transport properties of classical semiconductors (Si-based structures and CdSe colloidal nanoplatelets) as well as the dielectric properties are studied by DFT approaches and non-equilibrium Green's functions (NEGF).

Dangling bond wires current Selected publications

Electronic surface states and dielectric self-energy profiles in colloidal nanoscale platelets of CdSe
J. Even, L. Pedesseau, M. Kepenekian
Phys. Chem. Chem. Phys. 201416, 25182

Spin transport in dangling-bond wires on doped H-passivated Si(100)
M. Kepenekian, R. Robles, R. Rurali, N. Lorente
Nanotechnology 201425, 465703

Surface-state engineering for interconnects on H-passivated Si(100)
M. Kepenekian, R. Robles, C. Joachim, N. Lorente
Nano Lett. 201313, 1192

 

Skills & Interests

Physico-chemistry of magnetic and redox molecular systems
Surface properties of metals and semiconductors
Transport properties of materials and molecules
Physical properties of materials for photovoltaics

Ab initio wavefunction-based multireference molecular calculations (CASSCF, CASPT2, DDCI)
Molecular and periodic calculations based on density functional theory (DFT)
Description of excited states and out-of-equilibrium states through Green’s functions

Education and previous positions

2010-2013 | CSIC Postdoctoral fellow
Institut Catala de Nanociancia I Nanotecnologia (ICN2, Bellaterra, Spain)
Host: Prof. N. Lorente

2007-2010 | PhD in Theoretical Chemistry
Commissariat à l’Energie Atomique (Grenoble, France)
École Normale Supérieure de Lyon (Lyon, France)
Advisors: Dr. P. Maldivi (CEA Grenoble) & Dr. V. Robert (ENS Lyon)
Title: 'Ab initio inspection of magnetic and redox hysteresis'
Gaston Berthier PhD award from the French Network for Theoretical Chemistry

2005-2007 | Master degree in Material Sciences
École Normale Supérieure de Lyon (Lyon, France)
Major: Physical Chemistry

Publications referenced in HAL (non-exhaustive list)