| Autor: |
Stuckelberger, M., Park, B.-S., Bugnon, G., Despeisse, M., Schüttauf, J.-W., Haug, F.-J., Ballif, C. |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 11/16/2015, Vol. 107 Issue 20, p201112-1-201112-5, 5p, 1 Diagram, 1 Chart, 6 Graphs |
| Abstrakt: |
The boron-tailing effect in hydrogenated amorphous silicon (α-Si:H) solar cells describes the reduced charge collection specifically in the blue part of the spectrum for absorber layers deposited above a critical temperature. This effect limits the device performance of state-of-the art solar cells: For enhanced current density (reduced bandgap), the deposition temperature should be as high as possible, but boron tailing gets detrimental above 200 °C. To investigate this limitation and to show potential paths to overcome it, we deposited high-efficiency α-Si:H solar cells, varying the deposition temperatures of the p-type and the intrinsic absorber (i) layers between 150 and 250 °C. Using secondary ion mass spectroscopy, we study dedicated stacks of i-p-i layers deposited at different temperatures. This allows us to track boron diffusion at the p-i and i-p interfaces as they occur in the p-i-n and n-i-p configurations of a-Si:H solar cells for different deposition conditions. Finally, we prove step-by-step that the common explanation for boron tailing--boron diffusion from the p layer into the i layer leading to enhanced recombination--is not generally true and propose an alternative explanation for the experimentally observed drop in the external quantum efficiency at short wavelengths. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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