Abstract
Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve fullatomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface ismaximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.
Original language | American English |
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Number of pages | 5 |
State | Published - 2011 |
Event | 37th IEEE Photovoltaic Specialists Conference (PVSC 37) - Seattle, Washington Duration: 19 Jun 2011 → 24 Jun 2011 |
Conference
Conference | 37th IEEE Photovoltaic Specialists Conference (PVSC 37) |
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City | Seattle, Washington |
Period | 19/06/11 → 24/06/11 |
NREL Publication Number
- NREL/CP-5200-50730
Keywords
- atomic scale characterization
- III-V
- multijunction
- PV
- solar cells