First-principles calculation of optical absorption spectra in conjugated polymers: role of electron-hole interaction

Experimental and theoretical studies have shown that excitonic effects play an important role in the optical properties of conjugated polymers. The op tical absorption spectrum of trans-polyacetylene, for example, can be under stood as completely dominated by the formation of exciton bound states. We review a recently developed first-principles method for computing the excit onic effects and optical spectrum, with no adjustable parameters. This theo ry is used to study the absorption spectrum of two conjugated polymers: tra nspolyacetylene and poly-phenylene-vinylene (PPV). (C) 2001 Elsevier Scienc e B.V. All rights reserved.