2008/11/15 by Brad Conrad, B. R. Conrad, B.R. Conrad +9 · 1 citation
Engineering · Physics and Astronomy · #Force Microscopy Techniques and Applications #Organic Electronics and Photovoltaics #Surface and Thin Film Phenomena #cond-mat.mtrl-sci
paper · pdf · doi:10.1016/j.susc.2008.12.020
15 pages, 4 figures
arxiv created 2008/11/15 · openalex publication_date 2008/12/26 · crossref created 2008/12/26 · crossref issued 2009/02/01 · crossref published 2009/02/01 · crossref published-print 2009/02/01 · arxiv updated 2015/05/12 · crossref deposited 2018/12/23 · crossref indexed 2023/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Ultra-thin oxide (UTO) films were grown on Si(111) in ultrahigh vacuum at room temperature and characterized by scanning tunneling microscopy. The ultra-thin oxide films were then used as substrates for room temperature growth of pentacene. The apparent height of the first layer is 1.57 +/- 0.05 nm, indicating standing up pentacene grains in the thin-film phase were formed. Pentacene is molecularly resolved in the second and subsequent molecular layers. The measured in-plane unit cell for the pentacene (001) plane (ab plane) is a=0.76+/-0.01 nm, b=0.59+/-0.01 nm, and gamma=87.5+/-0.4 degrees. The films are unperturbed by the UTO's short-range spatial variation in tunneling probability, and reduce its corresponding effective roughness and correlation exponent with increasing thickness. The pentacene surface morphology follows that of the UTO substrate, preserving step structure, the long range surface rms roughness of ~0.1 nm, and the structural correlation exponent of ~1.