Details
| Original language | English |
|---|---|
| Pages (from-to) | 223-228 |
| Number of pages | 6 |
| Journal | Solid State Phenomena |
| Volume | 95-96 |
| Publication status | Published - 2004 |
| Externally published | Yes |
| Event | Gettering and Defect Engineering in Semiconductor Technology GADEST 2003: 10th International Autumn Meeting - Brandenburg, Germany Duration: 21 Sept 2003 → 26 Sept 2003 |
Abstract
The efficiency of silicon solar cells made on boron-doped Czochralski silicon is known to degrade under illumination. A boron- and oxygen-related metastable defect has been held responsible for this performance loss. This paper aims at clarifying the quantitative dependence of the metastable defect density on the boron and oxygen concentration. In order find knew strategies for the reduction of the degradation a fundamental understanding of the physical mechanism underlying the defect formation is essential. Therefore, we have investigated the time and temperature dependence of the degradation of the carrier lifetime and open-circuit voltage in detail. The defect formation process can be characterized by a two-step mechanism. The initial degradation is extremely fast taking place on a time scale of seconds and is not thermally activated, whereas the asymptotic degradation occurs on a time scale of hours and is thermally activated. The activation energy has been determined to be only 0.37 eV. The second part of the paper aims at optimizing the solar cell emitter diffusion process in order to reduce the performance loss. We show that it is possible to reduce the normalized defect density significantly by a factor of up to 3.5 with an optimized phosphorus diffusion at 850°C in a conventional quartz tube furnace using fast ramping conditions.
Keywords
- Carrier Lifetime, Czochralski, Defects, Degradation, Metastability, Silicon, Solar Cell
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Solid State Phenomena, Vol. 95-96, 2004, p. 223-228.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Understanding and Reducing the Boron-Oxygen-Related Performance Degradation in Czochralski Silicon Solar Cells
AU - Bothe, Karsten
AU - Hezel, Rudolf
AU - Schmidt, Jan
PY - 2004
Y1 - 2004
N2 - The efficiency of silicon solar cells made on boron-doped Czochralski silicon is known to degrade under illumination. A boron- and oxygen-related metastable defect has been held responsible for this performance loss. This paper aims at clarifying the quantitative dependence of the metastable defect density on the boron and oxygen concentration. In order find knew strategies for the reduction of the degradation a fundamental understanding of the physical mechanism underlying the defect formation is essential. Therefore, we have investigated the time and temperature dependence of the degradation of the carrier lifetime and open-circuit voltage in detail. The defect formation process can be characterized by a two-step mechanism. The initial degradation is extremely fast taking place on a time scale of seconds and is not thermally activated, whereas the asymptotic degradation occurs on a time scale of hours and is thermally activated. The activation energy has been determined to be only 0.37 eV. The second part of the paper aims at optimizing the solar cell emitter diffusion process in order to reduce the performance loss. We show that it is possible to reduce the normalized defect density significantly by a factor of up to 3.5 with an optimized phosphorus diffusion at 850°C in a conventional quartz tube furnace using fast ramping conditions.
AB - The efficiency of silicon solar cells made on boron-doped Czochralski silicon is known to degrade under illumination. A boron- and oxygen-related metastable defect has been held responsible for this performance loss. This paper aims at clarifying the quantitative dependence of the metastable defect density on the boron and oxygen concentration. In order find knew strategies for the reduction of the degradation a fundamental understanding of the physical mechanism underlying the defect formation is essential. Therefore, we have investigated the time and temperature dependence of the degradation of the carrier lifetime and open-circuit voltage in detail. The defect formation process can be characterized by a two-step mechanism. The initial degradation is extremely fast taking place on a time scale of seconds and is not thermally activated, whereas the asymptotic degradation occurs on a time scale of hours and is thermally activated. The activation energy has been determined to be only 0.37 eV. The second part of the paper aims at optimizing the solar cell emitter diffusion process in order to reduce the performance loss. We show that it is possible to reduce the normalized defect density significantly by a factor of up to 3.5 with an optimized phosphorus diffusion at 850°C in a conventional quartz tube furnace using fast ramping conditions.
KW - Carrier Lifetime
KW - Czochralski
KW - Defects
KW - Degradation
KW - Metastability
KW - Silicon
KW - Solar Cell
UR - http://www.scopus.com/inward/record.url?scp=1642479264&partnerID=8YFLogxK
M3 - Conference article
AN - SCOPUS:1642479264
VL - 95-96
SP - 223
EP - 228
JO - Solid State Phenomena
JF - Solid State Phenomena
SN - 1012-0394
T2 - Gettering and Defect Engineering in Semiconductor Technology GADEST 2003
Y2 - 21 September 2003 through 26 September 2003
ER -