کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5369652 1388447 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modification of the electronic properties of the TiO2 (1 1 0) surface upon deposition of the ultrathin conjugated organic layers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Modification of the electronic properties of the TiO2 (1 1 0) surface upon deposition of the ultrathin conjugated organic layers
چکیده انگلیسی

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 TiO2 (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 (EF) 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/TiO2 (1 1 0) interface and from 4.6 to 4.3 eV at the CuPc/TiO2 (1 1 0) interface. Band bending in the TiO2 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 TiO2 (1 1 0) upon elevating temperature from 25 to 400 °C was suggested.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 253, Issue 18, 15 July 2007, Pages 7376-7380
نویسندگان
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