Details
| Original language | English |
|---|---|
| Pages (from-to) | 42020-42028 |
| Number of pages | 9 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 9 |
| Issue number | 48 |
| Publication status | Published - 14 Nov 2017 |
Abstract
The great majority of electronic and optoelectronic devices depend on interfaces between p-type and n-type semiconductors. Finding matching donor-acceptor systems in molecular semiconductors remains a challenging endeavor because structurally compatible molecules may not necessarily be suitable with respect to their optical and electronic properties, and the large exciton binding energy in these materials may favor bound electron-hole pairs rather than free carriers or charge transfer at an interface. Regardless, interfacial charge-transfer exciton states are commonly considered as an intermediate step to achieve exciton dissociation. The formation efficiency and decay dynamics of such states will strongly depend on the molecular makeup of the interface, especially the relative alignment of donor and acceptor molecules. Structurally well-defined pentacene-perfluoropentacene heterostructures of different molecular orientations are virtually ideal model systems to study the interrelation between molecular packing motifs at the interface and their electronic properties. Comparing the emission dynamics of the heterosystems and the corresponding unitary films enables accurate assignment of every observable emission signal in the heterosystems. These heterosystems feature two characteristic interface-specific luminescence channels at around 1.4 and 1.5 eV that are not observed in the unitary samples. Their emission strength strongly depends on the molecular alignment of the respective donor and acceptor molecules, emphasizing the importance of structural control for device construction.
Keywords
- charge-transfer excitations, exciton dynamics, molecular crystals, organic heterostructures, organic thin films
ASJC Scopus subject areas
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: ACS Applied Materials and Interfaces, Vol. 9, No. 48, 14.11.2017, p. 42020-42028.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Interfacial Molecular Packing Determines Exciton Dynamics in Molecular Heterostructures
T2 - The Case of Pentacene-Perfluoropentacene
AU - Rinn, Andre
AU - Breuer, Tobias
AU - Wiegand, Julia
AU - Beck, Michael
AU - Hübner, Jens
AU - Döring, Robin C.
AU - Oestreich, Michael
AU - Heimbrodt, Wolfram
AU - Witte, Gregor
AU - Chatterjee, Sangam
N1 - Funding information: J.W. and M.B. acknowledge financial support by the DFG research training group RTG1991. Financial support was provided through SFB 1083 Structure and Dynamics of Internal Interfaces. Additionally, S.C. acknowledges financial support through the Heisenberg program of the German Science Foundation (CH660/2). J.W. and M.B. acknowledge financial support by the DFG research training group RTG1991. Financial support was provided through SFB 1083 “Structure and Dynamics of Internal Interfaces”. Additionally, S.C. acknowledges financial support through the Heisenberg program of the German Science Foundation (CH660/2).
PY - 2017/11/14
Y1 - 2017/11/14
N2 - The great majority of electronic and optoelectronic devices depend on interfaces between p-type and n-type semiconductors. Finding matching donor-acceptor systems in molecular semiconductors remains a challenging endeavor because structurally compatible molecules may not necessarily be suitable with respect to their optical and electronic properties, and the large exciton binding energy in these materials may favor bound electron-hole pairs rather than free carriers or charge transfer at an interface. Regardless, interfacial charge-transfer exciton states are commonly considered as an intermediate step to achieve exciton dissociation. The formation efficiency and decay dynamics of such states will strongly depend on the molecular makeup of the interface, especially the relative alignment of donor and acceptor molecules. Structurally well-defined pentacene-perfluoropentacene heterostructures of different molecular orientations are virtually ideal model systems to study the interrelation between molecular packing motifs at the interface and their electronic properties. Comparing the emission dynamics of the heterosystems and the corresponding unitary films enables accurate assignment of every observable emission signal in the heterosystems. These heterosystems feature two characteristic interface-specific luminescence channels at around 1.4 and 1.5 eV that are not observed in the unitary samples. Their emission strength strongly depends on the molecular alignment of the respective donor and acceptor molecules, emphasizing the importance of structural control for device construction.
AB - The great majority of electronic and optoelectronic devices depend on interfaces between p-type and n-type semiconductors. Finding matching donor-acceptor systems in molecular semiconductors remains a challenging endeavor because structurally compatible molecules may not necessarily be suitable with respect to their optical and electronic properties, and the large exciton binding energy in these materials may favor bound electron-hole pairs rather than free carriers or charge transfer at an interface. Regardless, interfacial charge-transfer exciton states are commonly considered as an intermediate step to achieve exciton dissociation. The formation efficiency and decay dynamics of such states will strongly depend on the molecular makeup of the interface, especially the relative alignment of donor and acceptor molecules. Structurally well-defined pentacene-perfluoropentacene heterostructures of different molecular orientations are virtually ideal model systems to study the interrelation between molecular packing motifs at the interface and their electronic properties. Comparing the emission dynamics of the heterosystems and the corresponding unitary films enables accurate assignment of every observable emission signal in the heterosystems. These heterosystems feature two characteristic interface-specific luminescence channels at around 1.4 and 1.5 eV that are not observed in the unitary samples. Their emission strength strongly depends on the molecular alignment of the respective donor and acceptor molecules, emphasizing the importance of structural control for device construction.
KW - charge-transfer excitations
KW - exciton dynamics
KW - molecular crystals
KW - organic heterostructures
KW - organic thin films
UR - http://www.scopus.com/inward/record.url?scp=85037709979&partnerID=8YFLogxK
U2 - 10.1021/acsami.7b11118
DO - 10.1021/acsami.7b11118
M3 - Article
C2 - 29135216
AN - SCOPUS:85037709979
VL - 9
SP - 42020
EP - 42028
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
SN - 1944-8244
IS - 48
ER -