Defect-induced shift of the Peierls transition in TTF-TCNQ thin films

In this paper we investigate the influence of the substrate material and film thickness on the Peierls transition temperature in tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) thin films, grown by physical vapor deposition. Our analysis shows that the substrate material and the growth conditions strongly influence the film morphology. In particular, we demonstrate that the Peierls transition temperature in thin films is lower than in TTF-TCNQ single crystals. We argue that this effect arises due to defects, which emerge in TTF-TCNQ thin films during the growth process.