Abstract
The p-type semiconducting properties of a triphenylene-fused triindole mesogen, have been studied by applying two complementary methods which have different alignment requirements. The attachment of only three flexible alkyl chains to the nitrogen atoms of this π-extended core is sufficient to induce columnar mesomorphism. High hole mobility values (0.65 cm2 V-1 s-1) have been estimated by space-charge limited current (SCLC) measurements in a diode-like structure which are easily prepared from the melt, rendering this material a good candidate for OPVs and OLEDs devices. The mobility predicted theoretically via a hole-hopping mechanism is in very good agreement with the experimental values determined at the SCLC regime. On the other hand the hole mobility determined on solution processed thin film transistors (OFETs) is significantly lower, which can be rationalized by the high tendency of these large molecules to align on surfaces with their extended π-conjugated core parallel to the substrate as demonstrated by SERS. Despite the differences obtained with the two methods, the acceptable performance found on OFETs fabricated by simple drop-casting processing of such an enlarged aromatic core is remarkable and suggests facile hopping between neighboring molecular columns owing to the large conducting/isolating ratio found in this discotic compound.
| Original language | English |
|---|---|
| Pages (from-to) | 26964-26971 |
| Number of pages | 8 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 8 |
| Issue number | 40 |
| DOIs | |
| Publication status | Published - Oct 12 2016 |
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Keywords
- discotic liquid-crystals
- hole mobility
- OFETS
- organic semiconductors
- SCLC measurements
ASJC Scopus subject areas
- Materials Science(all)
Cite this
Mobility versus Alignment of a Semiconducting π-Extended Discotic Liquid-Crystalline Triindole. / Ruiz, Constanza; Pandey, Upendra K.; Termine, Roberto; García-Frutos, Eva M.; López-Espejo, Guzmán; Ortiz, Rocío Ponce; Huang, Wei; Marks, Tobin J; Facchetti, Antonio; Ruiz Delgado, M. Carmen; Golemme, Attilio; Gómez-Lor, Berta.
In: ACS Applied Materials and Interfaces, Vol. 8, No. 40, 12.10.2016, p. 26964-26971.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mobility versus Alignment of a Semiconducting π-Extended Discotic Liquid-Crystalline Triindole
AU - Ruiz, Constanza
AU - Pandey, Upendra K.
AU - Termine, Roberto
AU - García-Frutos, Eva M.
AU - López-Espejo, Guzmán
AU - Ortiz, Rocío Ponce
AU - Huang, Wei
AU - Marks, Tobin J
AU - Facchetti, Antonio
AU - Ruiz Delgado, M. Carmen
AU - Golemme, Attilio
AU - Gómez-Lor, Berta
PY - 2016/10/12
Y1 - 2016/10/12
N2 - The p-type semiconducting properties of a triphenylene-fused triindole mesogen, have been studied by applying two complementary methods which have different alignment requirements. The attachment of only three flexible alkyl chains to the nitrogen atoms of this π-extended core is sufficient to induce columnar mesomorphism. High hole mobility values (0.65 cm2 V-1 s-1) have been estimated by space-charge limited current (SCLC) measurements in a diode-like structure which are easily prepared from the melt, rendering this material a good candidate for OPVs and OLEDs devices. The mobility predicted theoretically via a hole-hopping mechanism is in very good agreement with the experimental values determined at the SCLC regime. On the other hand the hole mobility determined on solution processed thin film transistors (OFETs) is significantly lower, which can be rationalized by the high tendency of these large molecules to align on surfaces with their extended π-conjugated core parallel to the substrate as demonstrated by SERS. Despite the differences obtained with the two methods, the acceptable performance found on OFETs fabricated by simple drop-casting processing of such an enlarged aromatic core is remarkable and suggests facile hopping between neighboring molecular columns owing to the large conducting/isolating ratio found in this discotic compound.
AB - The p-type semiconducting properties of a triphenylene-fused triindole mesogen, have been studied by applying two complementary methods which have different alignment requirements. The attachment of only three flexible alkyl chains to the nitrogen atoms of this π-extended core is sufficient to induce columnar mesomorphism. High hole mobility values (0.65 cm2 V-1 s-1) have been estimated by space-charge limited current (SCLC) measurements in a diode-like structure which are easily prepared from the melt, rendering this material a good candidate for OPVs and OLEDs devices. The mobility predicted theoretically via a hole-hopping mechanism is in very good agreement with the experimental values determined at the SCLC regime. On the other hand the hole mobility determined on solution processed thin film transistors (OFETs) is significantly lower, which can be rationalized by the high tendency of these large molecules to align on surfaces with their extended π-conjugated core parallel to the substrate as demonstrated by SERS. Despite the differences obtained with the two methods, the acceptable performance found on OFETs fabricated by simple drop-casting processing of such an enlarged aromatic core is remarkable and suggests facile hopping between neighboring molecular columns owing to the large conducting/isolating ratio found in this discotic compound.
KW - discotic liquid-crystals
KW - hole mobility
KW - OFETS
KW - organic semiconductors
KW - SCLC measurements
UR - http://www.scopus.com/inward/record.url?scp=84991290256&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84991290256&partnerID=8YFLogxK
U2 - 10.1021/acsami.6b06241
DO - 10.1021/acsami.6b06241
M3 - Article
AN - SCOPUS:84991290256
VL - 8
SP - 26964
EP - 26971
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 40
ER -