Study The Structural, Electronic And Optical Properties Of New Nitride Material Algainn By The Ab-initio Method (fp-lapw).

Résumé: In this thesis, the main objective is to investigate new nitrides materials, at first a theoretical part based on the full-potential linearized augmented plane wave method (FP-LAPW) based density functional theory (DFT) which was implemented in WIEN2K code employed throughout the work to investigate the structural, electronic and optical properties of the compound GaN, AlN, InN, ternary 〖Al〗_(1-y) 〖Ga〗_y N, and quaternary 〖Al〗_x 〖Ga〗_y 〖In〗_(1-x-y) N zinc-blende alloys matched on AlN substrate using 64-atom supercell. As well as the study of the structural and optoelectronic properties of the Wurtzite 〖In〗_x 〖Ga〗_(1-x) N matched on GaN substrate using 16-atom supercell. The generalized gradient approximation of Wu and Cohen (WC-GGA), the standard local density approach (LDA) and the modified Becke-Johnson exchange potential [F. Tran and P. Blaha] (TB-mBJ) were applied to improve the band structure and optical properties for the compounds. Whenever conceivable, we compare the obtained results by experiments and computations performed with diverse computational schemes. The second part is the experiment which is the application of the wurtzite structure III/V nitride ternary alloys 〖In〗_x 〖Ga〗_(1-x) N, by a solar cell grown by metal-organic chemical vapor deposition (MOCVD) equipment SR2000KS with a horizontal reactor manufactured by Taiyo Nippon Sanso. The InGaN/ GaN solar cells structures were growth on 2-inch Si substrate with (111)-crystal orientation. Cross-section scanning using field effect scanning electron microscopy (FESEM) technique was conducted to further confirm the homogeneity of grown the AlN nucleation layer, multi-layer (ML) and multi quantum well (MQW) on Si (111) substrate.

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