Structural, electronic, and linear optical properties of organic photovoltaic PBTTT-C14 crystal.
J Chem Phys
; 138(16): 164503, 2013 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-23635153
ABSTRACT
Poly(2,5-bis(3-tetradecylthiophen-2yl)thieno(3,2-b)thiophene) (PBTTT-C14) is an important electro-optical polymer, whose three-dimensional crystal structure is somewhat ambiguous and the fundamental electronic and linear optical properties are not well known. We carried out first-principles calculations to model the crystal structure and to study the effect of side-chains on the physical structure and electronic properties. Our calculations suggest that the patterns of side-chain has little direct effect on the valence band maximum and conduction band minimum but they do have impact on the bandgap through changing the π-π stacking distance. By examining the band structure and wave functions, we conclude that the fundamental bandgap of the PBTTT-C14 crystal is determined by the conduction band energy at the Q point. The calculations indicate that the bandgap of PBTTT-C14 crystal may be tunable by introducing different side-chains. The significant peak in the imaginary part of the dielectric function arises from transitions along the polymer backbone axis, as determined by the critical-point analysis and the large optical transition matrix elements in the direction of the backbone.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polímeros
/
Fontes de Energia Elétrica
/
Tiofenos
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos