Dresden 2009 – wissenschaftliches Programm
DS 16.29: Poster
Dienstag, 24. März 2009, 09:30–12:30, P5
Dependence of the deposition conditions on ZnO Surface morphology — •Viola Mönkemöller1, Florian Lükermann1, Marc Sacher1, Armin Brechling1, Ulrich Heinzmann1, Henning Kurz2, Frank Hamelmann2, and Helmut Stiebig2 — 1Molecular and Surface Physics, Bielefeld University, Germany — 2Malibu GmbH, Bielefeld, Germany
Boron doped ZnO films deposited by Low Pressure Chemical Vapour Deposition are used as transparent conductive oxide (TCO) for thin film solar cells. The films show an interesting surface morphology composed of pyramidal grains, which are formed due to a pronounced orientation of the  crystallographic axis perpendicular to the surface. 
We performed AFM measurements on ZnO films to investigate the change in surface morphology with respect to the depostion conditions such as deposition time, temperature and the boron doping concentration. We found that the thicker the films, the larger the pyramids and in contrast the higher the boron doping, the smaller the pyramids. For a varied depostion temperature we observed a change in crystallographic orientation by XRD measurements arround 160 ∘C from a pronounced  to a  axis growth. This change was also detected by AFM measurements due to a drastic change in surface morphology. Films below 160 ∘C show a nearly flat surface whereas films above that temperature show a rough surface of pyramidal structures.
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