Abstract
We calibrate the secondary electron signal from a standard scanning electron microscope to voltage, yielding an image of the surface or near-surface potential. Data on both atomically abrupt heterojunction GaInP/GaAs and diffused homojunction Si solar cell devices clearly show the expected variation in potential with position and applied bias, giving depletion widths and locating metallurgical junctions to an accuracy better than 10 nm. In some images, distortion near the p-n junction is observed, seemingly consistent with the effects of lateral electric fields (patch fields). Reducing the tube bias removes this distortion. This approach results in rapid and straightforward collection of near-surface potential data using a standard scanning electron microscope.
Original language | American English |
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Article number | 046103 |
Number of pages | 3 |
Journal | Journal of Applied Physics |
Volume | 111 |
Issue number | 4 |
DOIs | |
State | Published - 15 Feb 2012 |
NREL Publication Number
- NREL/JA-5200-54747
Keywords
- scanning electron microscope
- semiconductor measurement
- surface potential