Epitaxial Growth of C₆₀ on Rubrene Single Crystals for a Highly Ordered Organic Donor/Acceptor Interface

Abstract

The highly ordered epitaxial growth of C 60 films on rubrene single crystals was demonstrated. The C 60 crystals growth commensurate with rubrene (001) surface lattice was confirmed by reflection high energy electron diffraction and X-ray diffraction and grazing incident wide-angle X-ray scattering. Depending on growth conditions, several surface morphologies (rounded, hexagonal, and triangular grains) of C 60 grains were observed at the initial growth process. Large grains with layer-bylayer step and terrace structure of C 60 were observed at the terrace region of rubrene (001) surface. The growth of highcrystallinity C 60 films was achieved at high substrate temperature and slow deposition rate. Long migration length on the substrate which was given by enough substrate temperature enabled the formation of large single crystalline domains.

Photoelectron spectroscopy on single crystals of organic semiconductors: experimental electronic band structure for optoelectronic properties

“…On the other hand, structural analyses have disclosed well-defined assembly of several organic semiconductor molecules via heteroepitaxial growth on molecular single crystal substrates. [243][244][245][246][247][248][249][250] For instance, it was demonstrated by means of surface X-ray diffraction works that n-type semiconductor molecules of C 60 245 and perfluoropentacene (PFP; C 22 F 14 ) 250 form uniquely oriented crystallites on the single crystal surface of pentacene, and the mean size of these epitaxial crystallites reaches the 100 nm order. 246,248 Before closing this article, photoemission analyses conducted on these well-defined molecular-molecular heterointerfaces built on the Pn-SC will be summarized in the following paragraphs.…”

Electronic and Crystallographic Examinations of the Homoepitaxially Grown Rubrene Single Crystals

“…PYS is a suitable methodology for electronic characterization of specimens of low electric conductance [24,25], which is the case for intrinsic rubrene as a wide-gap (2.8 eV [26]) semiconductor, and particularly for detecting small modifications at the highest-occupied electronic states in an extreme sensitivity [27][28][29]. GIXD is a technique for determination of the crystal structures of thin films, and has successfully been applied to hetero-epitaxial organic semiconductor junctions built on molecular single crystals for specification of the lattice orientations [30][31][32] and even for evaluation of their crystallographic qualities by using high-resolution apparatuses [33][34][35]. It was confirmed that homoepitaxial rubrene single crystals grow without any apparent lattice distortion up to the thickness of 100 nm by the present GIXD measurements.…”

Organic Single Crystal Patterning Method for Micrometric Photosensors

“…Other organic materials, such as C 60 , or even inorganic materials, such as perovskite films, can also benefit from patterned rubrene acting as templates for epitaxial growth. [64,65] This work demonstrates the potential of RIE in patterning organic crystals without seriously damaging their performance and expands the possibilities for applying organic single crystal in practical electronic devices.…”