Pentacene islands grown on ultra-thin SiO2

SURFACE SCIENCE

卷:603

Article

Williams, E. D.¹ 

[1] Univ Maryland, Dept Phys, College Pk, MD 20742 USA

关键词: Scanning tunneling microscopy;    Nanotechnology;    Pentacene;    Ultra-thin oxide;    Silicon oxides;    Organic semiconductors;    Roughness;   

DOI  :  10.1016/j.susc.2008.12.020

来源: Elsevier

【 摘 要 】

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 (00 1) 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 similar to 0.1 nm, and the structural correlation exponent of similar to 1. (C) 2008 Elsevier B.V. All rights reserved.

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