Research output: Contribution to journal › Article › peer-review
Modification of the electronic properties of the TiO 2 (1 1 0) surface upon deposition of the ultrathin conjugated organic layers. / Komolov, A. S.; Møller, P. J.; Mortensen, J.; Komolov, S. A.; Lazneva, E. F.
In: Applied Surface Science, Vol. 253, No. 18, 15.07.2007, p. 7376-7380.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Modification of the electronic properties of the TiO 2 (1 1 0) surface upon deposition of the ultrathin conjugated organic layers
AU - Komolov, A. S.
AU - Møller, P. J.
AU - Mortensen, J.
AU - Komolov, S. A.
AU - Lazneva, E. F.
PY - 2007/7/15
Y1 - 2007/7/15
N2 - A few nm thick 3,4,9,10-perylenetetracarboxylic acid dianhydride (PTCDA) and Cu-phthalocyanine (CuPc) overlayers were thermally deposited in situ in UHV onto TiO 2 (1 1 0) surface. Atomic composition of the surfaces under study was monitored using Auger electron spectroscopy (AES). The formation of the interfacial potential barrier and the structure of the unoccupied electronic states located 5-25 eV above the Fermi level (E F ) was monitored using a probing beam of low-energy electrons according to the total current electron spectroscopy (TCS) method. The work function values upon the overlayer deposition changed from 4.6 to 4.9 eV at the PTCDA/TiO 2 (1 1 0) interface and from 4.6 to 4.3 eV at the CuPc/TiO 2 (1 1 0) interface. Band bending in the TiO 2 substrate, molecular polarization in the organic film and changes in the work function due to the change in the surface composition were found to contribute to the formation of the interfacial potential barriers. Oxygen admixture related peaks were observed in the AES and in the TCS spectra of the CuPc overlayers. A mechanism of the transformations in the PTCDA and CuPc overlayers on the TiO 2 (1 1 0) upon elevating temperature from 25 to 400 °C was suggested.
AB - A few nm thick 3,4,9,10-perylenetetracarboxylic acid dianhydride (PTCDA) and Cu-phthalocyanine (CuPc) overlayers were thermally deposited in situ in UHV onto TiO 2 (1 1 0) surface. Atomic composition of the surfaces under study was monitored using Auger electron spectroscopy (AES). The formation of the interfacial potential barrier and the structure of the unoccupied electronic states located 5-25 eV above the Fermi level (E F ) was monitored using a probing beam of low-energy electrons according to the total current electron spectroscopy (TCS) method. The work function values upon the overlayer deposition changed from 4.6 to 4.9 eV at the PTCDA/TiO 2 (1 1 0) interface and from 4.6 to 4.3 eV at the CuPc/TiO 2 (1 1 0) interface. Band bending in the TiO 2 substrate, molecular polarization in the organic film and changes in the work function due to the change in the surface composition were found to contribute to the formation of the interfacial potential barriers. Oxygen admixture related peaks were observed in the AES and in the TCS spectra of the CuPc overlayers. A mechanism of the transformations in the PTCDA and CuPc overlayers on the TiO 2 (1 1 0) upon elevating temperature from 25 to 400 °C was suggested.
KW - Conjugated organic molecules
KW - Metal oxide surfaces
KW - Surface electronic phenomena
KW - Titanium dioxide
UR - http://www.scopus.com/inward/record.url?scp=34249914797&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2007.03.024
DO - 10.1016/j.apsusc.2007.03.024
M3 - Article
VL - 253
SP - 7376
EP - 7380
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
IS - 18
ER -
ID: 18880871