Title :
Large area plan-view transmission electron microscopy sample preparation for multijunction metamorphic solar cell devices
Author :
Jackson, M.J. ; Jackson, B.L. ; Bodzin, N. ; Zakaira, A. ; Liu, X.-Q. ; King, R.R. ; Goorsky, M.S.
Author_Institution :
Dept. of Mater. Sci. & Eng., UCLA, Los Angeles, CA, USA
Abstract :
A focused ion beam (FIB) sample preparation technique is developed to produce very large areas of electron transparent material for plan-view transmission electron microscopy measurements from specific layers in a multi-layer device structure. An initial cross section FIB cut allows plan-view sample creation from any layer of interest, and therefore rapid characterization of the defect density as a function of depth is achievable for structures containing multiple layers, such as multi-junction metamorphic layer structures for high efficiency III-V solar cells. Uniform electron transparent plan-view areas of greater than 100 μm2 are extracted from a cross-section to facilitate observation of defect densities as low as ~106 cm-2. To demonstrate the technique, the active cell layers of two inverted metamorphic III-V solar cell structures have been imaged to reveal defect densities as high as 109 cm-2 and as low as 106 cm-2.
Keywords :
focused ion beam technology; solar cells; transmission electron microscopy; FIB sample preparation technique; electron transparent material; electron transparent plan-view areas; focused ion beam sample preparation technique; high efficiency III-V solar cells; initial cross section FIB cut; inverted metamorphic III-V solar cell structures; large area plan-view transmission electron microscopy sample preparation; multijunction metamorphic layer structures; multijunction metamorphic solar cell devices; multilayer device structure; plan-view sample creation; plan-view transmission electron microscopy measurements; Buffer layers; Ion beams; Performance evaluation; Photovoltaic cells; Substrates; Transmission electron microscopy; Defect characterization; TEM; metamorphic devices; plan view;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2012 38th IEEE
Conference_Location :
Austin, TX
Print_ISBN :
978-1-4673-0064-3
DOI :
10.1109/PVSC.2012.6317906