Photophysical and spectroscopic investigations on (oligo)thiophene-arylene step-ladder copolymers. The interplay of conformational relaxation and on-chain energy transfer. - Pina J; Seixas de Melo J; Burrows HD; Bünnagel TW; Dolfen D; Kudla CJ; Scherf U (The journal of physical chemistry. B, 2009)