Abstract
We report on a direct measurement of the spatial distribution of electrical potential on cross sections of hydrogenated amorphous silicon (a-Si:H) n-i-p solar cells using scanning Kelvin probe microscopy. We found that most voltage has dropped near the p/i interface up to ∼500 mm into the i-layer, but that the voltage flattens out near the n/i region for a device with i-layer thickness of ∼800 nm. However, the potential distributes approximate-linearly on the entire i-layer for a device with i-layer of ∼250 nm. The potential measurements suggest that the i-layer is slightly n-type (6-13 × 10 15/cm3), and the depletion width is ∼350-500 nm at the i/p interface. This depletion width provides a direct experimental evidence for the device design criteria that a-Si:H solar cells should be thinner than ∼500 nm, in the point view of electrical potential.
Original language | American English |
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Pages (from-to) | 203-207 |
Number of pages | 5 |
Journal | Thin Solid Films |
Volume | 472 |
Issue number | 1-2 |
DOIs | |
State | Published - 2005 |
NREL Publication Number
- NREL/JA-520-34406
Keywords
- Electrical properties and measurements
- Silicon
- Solar cells