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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Optical absorbance and band-gap engineering of (BN)(1-x)(C-2)(x) two-dimensional alloys: Phase separation and composition fluctuation effects

Texto completo
Autor(es):
Guilhon, I. ; Marques, M. ; Teles, L. K. ; Bechstedt, F.
Número total de Autores: 4
Tipo de documento: Artigo Científico
Fonte: Physical Review B; v. 95, n. 3 JAN 10 2017.
Citações Web of Science: 12
Resumo

The (BN)(1-x)(C2)(x) alloys are promising materials for band-gap engineering in two-dimensional electronics. In this work, we provide a complete scenario of statistical possibilities for the distribution of atoms and its influence on electronic and optical properties. Using first-principles calculations combined with the generalized quasichemical approximation to account for disorder effects, we study the properties of these two-dimensional alloys as a function of their average composition. Our results show that atomic arrangements with C-C and B-N bonds are energetically favored over the ones with B-B and N-N bonds, explaining the known tendency to phase separation, verified by a T-x phase diagram. We calculate the energy gap as a function of the composition considering both composition fluctuation and phase separation effects. Experimental data are discussed in this context. Finally, we obtain absorption spectra reproducing a two-peak pattern for intermediate carbon concentrations found experimentally and identified with phase-segregated instead of homogeneous alloys. (AU)

Processo FAPESP: 12/50738-3 - Estudo de pontos quânticos através de cálculos de primeiros princípios
Beneficiário:Ronaldo Rodrigues Pelá
Linha de fomento: Auxílio à Pesquisa - Regular