Atomic structure of light-induced efficiency-degrading defects in boron-doped Czochralski silicon solar cells
- Colorado School of Mines, Golden, CO (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Colorado School of Mines, Golden, CO (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
Boron-doped Czochralski (Cz) Si is the most commonly used semiconductor in the fabrication of solar cells. The minority carrier lifetime of boron-doped Cz Si decreases upon exposure to light due to B–O-related defects, which reduce the performance of ~109 solar modules worldwide. Using electron paramagnetic resonance (EPR), we have identified the spin-active paramagnetic signatures of this phenomenon and gained insights into its microscopic mechanism. We found a distinct defect signature, which diminished when the degraded sample was annealed. The second signature, a broad magnetic field spectrum, due to the unionized B acceptors, was present in the annealed state but vanished upon light exposure. These observations show that, on degradation, nearly all the ~1016 cm–3 B atoms in Cz Si complexed with interstitial O atoms, whereas only ~1012 cm–3 of these complexes created defects that were recombination-active. The formation rate of these recombination-active defects correlated with the decay of the minority carrier lifetime. Furthermore, the line shape parameters linked these defects to both B and O impurities in Cz Si.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- Grant/Contract Number:
- AC36-08GO28308; SETP DE-EE0008171; SETP DE-EE0008984
- OSTI ID:
- 1821415
- Alternate ID(s):
- OSTI ID: 1817242
- Report Number(s):
- NREL/JA-5900-79622; MainId:35843; UUID:3ee8736e-932d-4d80-b29f-4c55b0806c64; MainAdminID:62876
- Journal Information:
- Energy & Environmental Science, Vol. 2021, Issue 14; ISSN 1754-5692
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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