Electronic Structures of a Well-Defined Organic Hetero-Interface: C&lt;sub&gt;60 &lt;/sub&gt;on Pentacene Single Crystal

Yamamoto, Masayuki; Nakayama, Yasuo; Uragami, Yuki; Kinjo, Hiroumi; Mizuno, Yuta; Mase, Kenji; Koswattage, Kaveenga Rasika; Ishii, Hisao

doi:10.1380/ejssnt.2015.59

Cited by 22 publications

(25 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On account of the formation of electronic bands and the associated delocalization of charge carriers, [1][2][3] reasonably high charge carrier mobility has been reported in devices of single crystalline organic semiconductors. Figure 2 insets show typical AFM images of the Pn-SC samples covered with 20 nm-thick C 60 overlayers grown at various substrate temperatures, i.e., 160, 300, and 370 K. C 60 forms grains on the Pn-SC surface in the case of RT (300 K) growth as reported previously, [23,31] and it was found that the lateral sizes and shapes of these grains vary depending on the growth temperature. Proportional increase of the inplane mean crystallite size of C 60 with the growth temperature suggests importance of surface diffusion processes of the C 60 molecules on the Pn-SC surface as a leading factor for determination of the heterojunction structures.…”

Section: Introductionsupporting

confidence: 63%

“…[15][16][17] In the present work, the evolution of the crystallinity of a well-ordered bimolecular heterojunction, C 60 on a single crystal surface of pentacene (C 22 H 14 ), is studied depending on the growth temperature by means of surface X-ray diffraction techniques and noncontact mode atomic force microscopy (nc-AFM). [18] The pentacene/C 60 interface has been studied widely, both experimentally [19][20][21][22][23][24] and theoretically. [18] The pentacene/C 60 interface has been studied widely, both experimentally [19][20][21][22][23][24] and theoretically.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene

Nakayama

Tsuruta

Hinderhofer

et al. 2018

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

due to charge carrier delocalization. [10][11][12][13][14] Accordingly, accurate control of the crystal quality of molecular heterojunctions is desired for advancing further development of next-generation organic electronic devices. [15][16][17] In the present work, the evolution of the crystallinity of a well-ordered bimolecular heterojunction, C 60 on a single crystal surface of pentacene (C 22 H 14 ), is studied depending on the growth temperature by means of surface X-ray diffraction techniques and noncontact mode atomic force microscopy (nc-AFM). Pentacene ( Figure 1a) and C 60 ( Figure 1b) are representative p-type (donor) and n-type (acceptor) semiconducting compounds generating an exciton-dissociating interface in a prototypical organic solar cell device. [18] The pentacene/C 60 interface has been studied widely, both experimentally [19][20][21][22][23][24] and theoretically. [25][26][27][28][29][30] It was recently discovered that C 60 crystallizes in its bulk structure epitaxially by aligning the nearest-neighbor face-centered-cubic (fcc)-110 < > axis uniquely along the [110] direction of the pentacene single crystal (Pn-SC) surface. [31] The type of this epitaxial interface is categorized into the incommensurism, whereas it is nearly of so-called "Type-IB" point-on-line coincidence [32] with a 6% lattice mismatch, as illustrated in Figure 1c. Moreover, the crystallographic coherence length of the C 60 overlayers grown at room temperature (RT) was found to exceed 100 nm in the in-plane directions. [33] The well-defined interface between Pn-SC and C 60 is ideally suited to study kinetic effects [34] in the growth of the topical donor-acceptor heterojunction. We herein demonstrate the crystallographic coherence of the C 60 overlayers on the Pn-SC as a function of the growth temperature through systematic Heteroepitaxy of one material onto another molecular single crystal surface is one promising route for resolving questions about formation criteria of molecular heterojunction structures as well as for the development of nextgeneration organic electronic devices allowing efficient intermolecular charge carrier exchange. In the present work, the in-plane and out-of-plane crystallinity of an epitaxial molecular p-n heterojunction, C 60 (acceptor) overlayers formed on the single crystal surface of pentacene (donor), and its evolution, depending on the growth temperature, are systematically elucidated. It is demonstrated that the crystallinity of the C 60 on pentacene is dominated by the temperature during the growth rather than the postannealing of the sample. The mean crystallite size in the in-plane directions grows from 50 to 150 nm proportionally to the growth temperature in a range of 125-370 K. The present results suggest that the formation mechanisms of the C 60 /pentacene heterojunction are kinetically controlled, by diffusion processes at the molecular interface, rather than by the thermal equilibrium conditions.

show abstract

Section: Introductionsupporting

confidence: 63%

mentioning

confidence: 99%

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene

Nakayama

Tsuruta

Hinderhofer

et al. 2018

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

show abstract

“…Yamamoto and co-authors carried out the high-resolution XPS and UPS measurements on the epitaxial heterointerface of C 60 on the Pn-SC samples. 251 The experimental setup was same as that described in Section III.2.(2). For the sake of deducing the interface electronic structures, evolution of the photoelectron spectra in the core-levels, valence bands, and secondary electron cut-off regions was systematically tracked as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

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

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this study, we consider the D/A bilayer heterojunction structure comprising pentacene as the electron donor and C 60 as the acceptor. The PEN/C 60 bilayer heterojunction is one of the most prototypical organic solar cells; 52,53 the electronic structures of the PEN/C 60 interfaces have been investigated in numerous studies, including ultraviolet photoelectron spectroscopy, [54][55][56] external quantum efficiency (EQE) measurements, 57,58 microelectrostatic calculations, 59 and ab initio methods. 8,9 According to the X-ray diffraction measurement, 57 the PEN/C 60 interface morphology is dominantly an edge-on orientation.…”

Section: B Application To Pen/c 60 Interfacementioning

confidence: 99%

Charge-transfer excited states in the donor/acceptor interface from large-scale GW calculations

Fujita

Noguchi

Hoshi

2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

Predicting the charge-transfer (CT) excited states across the donor/acceptor (D/A) interface is essential for understanding the charge photogeneration process in an organic solar cell. Here, we present a fragment-based GW implementation that can be applied to a D/A interface structure and thus enables accurate determination of the CT states. The implementation is based on the fragmentation approximation of the polarization function and the combined GW and Coulomb-hole plus screened exchange approximations for self-energies. The fragmentbased GW is demonstrated by application to the pentacene/C 60 interface structure containing more than 2000 atoms. The CT excitation energies were estimated from the quasiparticle energies and electron-hole screened Coulomb interactions; the computed energies are in reasonable agreement with experimental estimates from the external quantum efficiency measurements. We highlight the impact of the induced polarization effects on the electron-hole energetics. The proposed fragment-based GW method offers a first-principles tool to compute the quasiparticle energies and electronic excitation energies of organic materials.

show abstract

Electronic Structures of a Well-Defined Organic Hetero-Interface: C<sub>60 </sub>on Pentacene Single Crystal

Cited by 22 publications

References 38 publications

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene

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

Charge-transfer excited states in the donor/acceptor interface from large-scale GW calculations

Contact Info

Product

Resources

About

Electronic Structures of a Well-Defined Organic Hetero-Interface: C<sub>60 </sub>on Pentacene Single Crystal

Cited by 22 publications

References 38 publications

Temperature Dependent Epitaxial Growth of C60 Overlayers on Single Crystal Pentacene

Temperature Dependent Epitaxial Growth of C60 Overlayers on Single Crystal Pentacene

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

Charge-transfer excited states in the donor/acceptor interface from large-scale GW calculations

Contact Info

Product

Resources

About

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene

Temperature Dependent Epitaxial Growth of C₆₀ Overlayers on Single Crystal Pentacene