Electrical characterization of carbon nanotube metal matrix composite solar cell electrodes under mechanical stress

Metal matrix composites (MMCs) have been fabricated as potential advanced solar cell electrodes. Test structures have been developed for evaluating electrical performance of the MMC electrodes upon substrate fracture and under subsequent tensile stress to simulate stress fractures and mechanical fatigue of solar cell electrodes. Electrical analysis reveals that MMCs utilizing single-wall carbon nanotubes (SWCNTs) provide electrical continuity for gaps of ~6 μm or less; however, incorporation of longer multi-walled CNTs (MWCNTs) into the MMCs enables bridging of gaps approaching 30 μm. The results indicate that CNT-MMCs may provide a more robust solar cell electrode, particularly for fragile IMM solar cells.