Abstract
Overcoming the open circuit voltage deficiency in Cadmium Telluride (CdTe) photovoltaics may be achieved by increasing p-type doping while maintaining or increasing minority carrier lifetimes. Here, routes to higher doping efficiency using arsenic are explored through an atomic scale understanding of dopant incorporation limits and activation in molecular beam epitaxy grown CdTe layers. Atom probe tomography reveals spatial segregation into nanometer scale clusters containing > 60 at% As for samples with arsenic incorporation levels greater than 7–8 × 1017 cm−3. The presence of arsenic clusters was accompanied by crystal quality degradation, particularly the introduction of arsenic-enriched extended defects. Post-growth annealing treatments are shown to increase the size of the As precipitates and the amount of As within the precipitates.
Original language | American English |
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Pages (from-to) | 68-75 |
Number of pages | 8 |
Journal | Solar Energy Materials and Solar Cells |
Volume | 182 |
DOIs | |
State | Published - 1 Aug 2018 |
Bibliographical note
Publisher Copyright:© 2018 Elsevier B.V.
NREL Publication Number
- NREL/JA-5K00-71229
Keywords
- As doping
- Atom probe tomography
- CdTe
- Molecular beam epitaxy
- Scanning transmission electron microscopy
- Single crystalline