The study of molecular band offsets at the heteromolecular interface
by Xiao, Jie, Ph.D., THE UNIVERSITY OF NEBRASKA - LINCOLN, 2009, 136 pages; 3360091

Abstract:

This thesis covers a research effort to study molecular band offsets and the interplay with interface dipoles. Inorganic electrets and ferroelectrics typically have very poorly characterized surfaces and interfaces. In particular for the perovskites, surface and interface composition is more of a hope than a serial of materials with a good history of reproducible experimental characterization. To address these complexities, I have first focused on molecular systems and molecular heterostructures.

Obviously, strong interface dipoles are desirable for such studies. Such systems like polymethylvinylidenecyanide and a variety of ferroelectric polymers are described. All would serve as a suitable substrate.

My choice of adsorbate is the planar molecular metal centered macrocyclic semiconductor metal (II) phthalocyanines. The different metal phthalocyanines are compared, particularly with respect to the changes in 3d band filling/depletion, on a conducting substrate Au(111). This provides a benchmark for comparison of metal (II) phthalocyanine adsorption on the molecular ferroelectric polyvinylidene fluoride. There are changes in both of the molecular band offsets and the preferential orientations in the metal (II) phthalocyanines.

To add support to the idea that the molecular band offsets can be manipulated by altering the interface dipoles, I fabricated several heterostructure devices. Transport studies show unique hysteresis but support the observed molecular band offsets seen in the combined photoemission and inverse photoemission spectroscopies.

 
AdviserPeter A. Dowben
SchoolTHE UNIVERSITY OF NEBRASKA - LINCOLN
SourceDAI/B 70-06, p. , Aug 2009
Source TypeDissertation
SubjectsCondensed matter physics
Publication Number3360091
Adobe PDF Access the complete dissertation:
 

» Find an electronic copy at your library.
  Use the link below to access a full citation record of this graduate work:
  http://gateway.proquest.com/openurl%3furl_ver=Z39.88-2004%26res_dat=xri:pqdiss%26rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation%26rft_dat=xri:pqdiss:3360091
  If your library subscribes to the ProQuest Dissertations & Theses (PQDT) database, you may be entitled to a free electronic version of this graduate work. If not, you will have the option to purchase one, and access a 24 page preview for free (if available).

About ProQuest Dissertations & Theses
With over 2.3 million records, the ProQuest Dissertations & Theses (PQDT) database is the most comprehensive collection of dissertations and theses in the world. It is the database of record for graduate research.

The database includes citations of graduate works ranging from the first U.S. dissertation, accepted in 1861, to those accepted as recently as last semester. Of the 2.3 million graduate works included in the database, ProQuest offers more than 1.9 million in full text formats. Of those, over 860,000 are available in PDF format. More than 60,000 dissertations and theses are added to the database each year.

If you have questions, please feel free to visit the ProQuest Web site - http://www.proquest.com - or call ProQuest Hotline Customer Support at 1-800-521-3042.