Dresden 2006 – wissenschaftliches Programm
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O: Oberflächenphysik
O 27: Scanning probe techniques II
O 27.3: Vortrag
Dienstag, 28. März 2006, 16:15–16:30, WIL B321
Measurement and simulation of grain boundaries in thin film solar cell absorbers — •Caspar Leendertz, Ferdinand Streicher, Tobias Eisenbarth, Susanne Siebentritt, Sascha Sadewasser, and Martha Ch. Lux-Steiner — Hahn-Meitner-Institut, Glienicker Str. 100, 14109 Berlin
Kelvin probe force microscopy (KPFM) uses electrostatic forces for the spatially resolved measurement of surface potentials. Using KPFM we studied the potential barrier at grain boundaries of CuGaSe2 semiconductor thin films for solar cell applications. The long range electrostatic interaction complicates quantitative data interpretation. Therefore, we developed 3D simulations using finite element methods to estimate the spatial variation of the measured surface potentials as a function of the barrier height and doping concentration. We find that the deviation between measured and true barrier height strongly depends on the sample doping, i.e. the measured barrier height increases from 55% to 70% of the true barrier height when the doping drops from 5× 1016 cm−3 to 3× 1015 cm−3.