ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 Activity of our research group “Condensed matter and theoretical physics” Laboratoire de Physique et d’électronique (LPE) 7 researchers 4 PhD students (2010) 12 PhD students (2015) 35 papers in an international journals (2010-2015) 4 chapter in a book (2014) 20 conferences (2010-2015) Foundation of the M2R “fundamental physics” (2009) ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 First-principles investigation within the improved modified Becke–Johnson potential of CuInSe2 and CuGaSe2 Fouad EL HAJ HASSAN Université Libanaise, Faculté des sciences (I), Laboratoire de Physique et d’électronique (LPE), Elhadath, Beyrouth, Liban ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 Outline Introduction Method of calculations Density functional theory (DFT) Full potential-linearized augmented plan wave method (FP-LAPW) Results Structural and electronic properties Thermal properties Conclusions ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 Introduction Copper based chalcopyrite CuGaSe2 with its: Tetragonal structure High band gap High efficiency Widely used in Solar cells Light emitting diodes Nonlinear optics ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
Method of calculations Approximation M. Born R. Oppenheimer Born-Oppenheimer 1st International Conference on Numerical Physics, Oran, October 13-15, 2012
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 Hartree-Fock Theory D. Hartree V. Fock ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
Density functional theory DFT Kohn was awarded the Nobel prize in 1998 P. Hohenberg W. Kohn
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 LDA Kohn-Sham (1965) W. Kohn L.J. Sham ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 FP-LAPW method Potentiel Muffin-Tin Interstitial region Atomic sphere MT Rα ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
Results Structural properties F. El Haj Hassan et al, Phys. Rev. B 73 (2006) 195202.
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 F. El Haj Hassan et al, Sol.Energy 100 (2014) 1. Band structure Eg = 0.03 eV << Eg (experiment)= 1.68 eV Eg = 1.04 eV ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 F. El Haj Hassan et al, Sol. Energy 107 (2014) 543. ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
Density of states DOS Se Ga
Results (Electronic properties) Charge density along the plane (110) F. El Haj Hassan et al, Phys. Rev. B 81 (2010) 205213
Results (Thermodynamic Properties) Heat capacity & Thermal expansion α T3 ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
Results (Thermodynamic Properties) Debye temperature & Grüneisen parameter
Conclusions & Perspectives Applying FP-LAPW to CGS material GGA is accurate for the structural properties GGA underestimate the band gap CGS useful for solar cell technology Experimental study for the thermal properties Photoelectronic and optical investigations Structural phase transitions Study the Cu(In,Ga)Se2 Alloys ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015
ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015 Thank you for your attention For more information's you are invited to visit our website http://users.ictp.it/~fel_haj ICFPAM’2015, March 30–April 2, Marrakech, Morocco 2015